[go: up one dir, main page]

WO2016100349A2 - Bicyclic azaheterocyclic compounds as nr2b nmda receptor antagonists - Google Patents

Bicyclic azaheterocyclic compounds as nr2b nmda receptor antagonists Download PDF

Info

Publication number
WO2016100349A2
WO2016100349A2 PCT/US2015/065829 US2015065829W WO2016100349A2 WO 2016100349 A2 WO2016100349 A2 WO 2016100349A2 US 2015065829 W US2015065829 W US 2015065829W WO 2016100349 A2 WO2016100349 A2 WO 2016100349A2
Authority
WO
WIPO (PCT)
Prior art keywords
mmol
chemical entity
alkyl
methyl
carboxylate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2015/065829
Other languages
French (fr)
Other versions
WO2016100349A3 (en
Inventor
Gideon Shapiro
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rugen Holdings (cayman) Ltd
Original Assignee
Rugen Holdings (cayman) Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rugen Holdings (cayman) Ltd filed Critical Rugen Holdings (cayman) Ltd
Publication of WO2016100349A2 publication Critical patent/WO2016100349A2/en
Publication of WO2016100349A3 publication Critical patent/WO2016100349A3/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D487/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00
    • C07D487/02—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains two hetero rings
    • C07D487/04—Ortho-condensed systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A61P25/24—Antidepressants
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
    • C07D401/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D471/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, at least one ring being a six-membered ring with one nitrogen atom, not provided for by groups C07D451/00 - C07D463/00
    • C07D471/02—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, at least one ring being a six-membered ring with one nitrogen atom, not provided for by groups C07D451/00 - C07D463/00 in which the condensed system contains two hetero rings
    • C07D471/04—Ortho-condensed systems
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D491/00—Heterocyclic compounds containing in the condensed ring system both one or more rings having oxygen atoms as the only ring hetero atoms and one or more rings having nitrogen atoms as the only ring hetero atoms, not provided for by groups C07D451/00 - C07D459/00, C07D463/00, C07D477/00 or C07D489/00
    • C07D491/02—Heterocyclic compounds containing in the condensed ring system both one or more rings having oxygen atoms as the only ring hetero atoms and one or more rings having nitrogen atoms as the only ring hetero atoms, not provided for by groups C07D451/00 - C07D459/00, C07D463/00, C07D477/00 or C07D489/00 in which the condensed system contains two hetero rings
    • C07D491/04—Ortho-condensed systems
    • C07D491/044—Ortho-condensed systems with only one oxygen atom as ring hetero atom in the oxygen-containing ring
    • C07D491/048—Ortho-condensed systems with only one oxygen atom as ring hetero atom in the oxygen-containing ring the oxygen-containing ring being five-membered

Definitions

  • Non-selective NMDA receptor antagonists originally developed in stroke and head trauma, have more recently shown clinical efficacy in treating depression.
  • the non-selective NMDA receptor antagonist, ketamine has been shown to have rapid onset and efficacy in depression resistant to standard monoamine reuptake inhibitor therapy (Mathews and Zarate, 2013, J. Clin. Psychiatry 74:516-158).
  • non-selective NMDA receptor antagonists such as ketamine have a range of undesirable pharmacological activities which limit application in humans. In particular dissociative or psychogenic side effects are particularly prominent for non-selective NMDA receptor antagonists.
  • N 2B subtype selective NMDA receptor antagonists have demonstrated potential in a wide range of clinical indications.
  • NR2B antagonists have also demonstrated antidepressant activity in early stage clinical trials (Ibrahim et al., 2012, 7. Clin. Psychopharmacol. 32, 551-557; Preskorn et al., 2008, J. Clin. Psychopharmacol. 28, 631-637).
  • selective NR2B antagonists have advantages over unselective NMDA receptor antagonists such as ketamine due to greatly diminished dissociative side effects.
  • NR2B antagonists described to date have generally exhibited drawbacks with regard to other drug properties which have limited potential use in human drug therapy.
  • NR2B subtype selective antagonists are needed.
  • the present invention addresses the need for NR2B receptor antagonists that are improved in one or more aspects exemplified by pharmacokinetic performance, oral activity, cardiovascular safety, and in vitro and in vivo therapeutic safety index measures.
  • the present invention encompasses the insight that chemical entities of Formula (I):
  • R 1 and Z are NR2B subtype selective receptor antagonists.
  • Chemical entities of Formula (I), and pharmaceutically acceptable compositions thereof, are useful for treating a variety of diseases and disorders associated with NR2B receptor antagonism. Such diseases and disorders include those described herein.
  • FIG. 1 shows results of the Forced Swim Test as described in Example 2.2 with the compound El-1.2 ((3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate).
  • FIG. 2 shows results of the Forced Swim Test as described in Example 2.2 with the compound El-2.2 ((3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate).
  • the present invention provides chemical entities of Formula I:
  • R 1 is alkyl, cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl or (heteroaryl)alkyl, wherein each of cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl and (heteroaryl)alkyl is independently optionally substituted with 1 to 3 groups independently selected from -F, -CI, C C alkyl, cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , -Q alkoxy, -OCFH 2 , -OCF 2 H, -OCF 3 , -CN, -N(R 2 )
  • Z is 9- or 10-membered bicyclic ring system having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S, wherein said ring system : is a heteroaromatic ring system, which ring system is optionally substituted with 1 or 2 R x groups and optionally substituted with 1 R a group, wherein each R x is attached to a ring carbon atom and R a is attached to a ring nitrogen atom; or is a 5- or 6-membered heteroaryl in which two adjacent ring atoms are linked to form a 5- or 6- membered heterocycle, which ring system is optionally substituted with 1 or 2 R x groups and optionally substituted with 1 R b group, wherein each R x is attached to a ring carbon atom and R b is attached to a ring nitrogen atom; wherein: each instance of R x independently is -F, -CI, -CH 3 , -CFH 2
  • R a is Ci_4 alkyl, C 3 . 4 cycloalkyi or -S(0) 2 -C!_ 4 alkyl;
  • R b is Ci_ 4 alkyl, C 3 . 4 cycloalkyi, -C(0)-Ci_ 4 alkyl, -C(0)0-Ci_ 4 alkyl or -S(0) 2 -Ci_ 4 alkyl.
  • the term “chemical entity” refers to a compound having the indicated structure, whether in its “free” form (e.g., “free compound” or “free base” or “free acid” form, as applicable), or in a salt form, particularly a pharmaceutically acceptable salt form, and furthermore whether in solid state form or otherwise.
  • a solid state form is an amorphous (i.e., non-crystalline) form; in some embodiments, a solid state form is a crystalline form. In some embodiments, a crystalline form is a polymorph, pseudohydrate, or hydrate. Similarly, the term encompasses the compound whether provided in solid form or otherwise. Unless otherwise specified, all statements made herein regarding "compounds" apply to the associated chemical entities, as defined.
  • A can be a halogen, such as chlorine or bromine
  • A can be, but is not limited to, chlorine or bromine.
  • Chemical entities of this invention include those described generally above, and are further illustrated by the classes, subclasses, and species disclosed herein. As used herein, the following definitions shall apply unless otherwise indicated.
  • the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75 th Ed., inside cover, and specific functional groups are generally defined as described therein.
  • alkyl used alone or as part of a larger moiety, means a substituted or unsubstituted, linear or branched, univalent hydrocarbon chain that is completely saturated or that contains one or more units of unsaturation.
  • alkyl groups contain 1 to 7 carbon atoms ("Ci-Cy alkyl”). In some embodiments, alkyl groups contain 1 to 6 carbon atoms ("Ci-Q alkyl”). In some embodiments, alkyl groups contain 1 to 5 carbon atoms ("Ci-Cs alkyl”). In some embodiments, alkyl groups contain 1 to 4 carbon atoms (“Ci-C 4 alkyl”). In some embodiments, alkyl groups contain 3 to 7 carbon atoms (“C 3 -C 7 alkyl”).
  • saturated alkyl groups include methyl, ethyl, n- propyl, i-propyl, n-butyl, t-butyl, i-butyl, s-butyl, homologs and isomers of, for example, n-pentyl, n- hexyl, n-heptyl, n-octyl, and the like.
  • An unsaturated alkyl group is one having one or more carbon- carbon double bonds or carbon-carbon triple bonds.
  • Examples of unsaturated alkyl groups include allyl, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(l,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and the like.
  • the term "lower alkyl” refers to alkyl groups having 1 to 4 (if saturated) or 2 to 4 (if unsaturated) carbon atoms.
  • Exemplary lower alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl and the like.
  • alkenyl refers to alkyl groups having at least two carbon atoms and at least one carbon-carbon double bond.
  • alkynyl refers to alkyl groups having at least two carbon atoms and at least one carbon-carbon triple bond.
  • cycloalkyl used alone or as part of a larger moiety, e.g., "(cycloalkyl)alkyl”, refers to a univalent monocyclic hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic; or bicyclo[2.2.1]heptanyl (also called norbornyl) or bicyclo[2.2.2]octanyl.
  • cycloalkyl groups contain 3 to 8 ring carbon atoms ("C 3 -C 8 cycloalkyl").
  • cycloalkyl examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1- cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like, as well as bicyclo[2.2.1]heptanyl and bicyclo[2.2.2]octanyl.
  • alkoxy used alone or as part of a larger moiety, refers to the group -O-alkyl.
  • halogen or halo
  • aryl used alone or as part of a larger moiety, e.g., "(aryl)alkyl” refers to a univalent monocyclic or bicyclic carbocyclic aromatic ring system. Unless otherwise specified, aryl groups contain 6 or 10 ring members. Examples of aryl include phenyl, naphthyl, and the like.
  • heteroaryl used alone or as part of a larger moiety, e.g., "(heteroaryl)alkyl”, refers to a univalent monocyclic or bicyclic group having 5 to 10 ring atoms, preferably 5, 6, 9 or 10 ring atoms, having 6, 10, or 14 ⁇ electrons shared in a cyclic array, and having, in addition to ring carbon atoms, from one to four ring heteroatoms.
  • heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, and the like.
  • heterocyclyl used alone or as part of a larger moiety, e.g., "(heterocyclyl)alkyl”, refers to a univalent stable 5- to 7-membered monocyclic or 7- to 10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated, and having, in addition to ring carbon atoms, one to four heteroatoms.
  • heterocycyl groups include tetrahydrofuranyl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, and the like.
  • the term "pharmaceutically acceptable salt” refers to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio.
  • Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66:1-19, incorporated herein by reference.
  • Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases.
  • Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange.
  • inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid
  • organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange.
  • salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate,
  • Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N + (Ci_4 alkyl) 4 salts.
  • Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like.
  • Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate and aryl sulfonate.
  • structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, Z and E double bond isomers, and Z and E conformational isomers. Therefore, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, all tautomeric forms of the compounds of the invention are within the scope of the invention.
  • structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms.
  • compounds having the present structures including the replacement hydrogen, carbon, nitrogen, oxygen, chlorine or fluorine with 2 H, 3 H, n C, 13 C, 14 C, 1 3 N, 15 N, 17 0, 18 0, 36 CI or 18 F, respectively, are within the scope of this invention.
  • Such compounds are useful, for example, as analytical tools, as probes in biological assays, or as therapeutic agents in accordance with the present invention.
  • incorporation of heavier isotopes such as deuterium ( 2 H) can afford certain therapeutic advantages resulting from greater metabolic stability, for example, increase in vivo half-life, or reduced dosage requirements.
  • the present invention provides chemical entities of Formula (I):
  • R 1 and Z are as described above.
  • R 1 is optionally substituted alkyl.
  • R 1 is optionally substituted cycloalkyl or optionally substituted (cycloalkyl)alkyl. In some embodiments, R 1 is optionally substituted cycloalkyl. In some embodiments, R 1 is optionally substituted cyclohexyl. In some embodiments, R 1 is cyclohexyl. In some embodiments, R 1 is 4,4-difluorocyclohexyl. In some embodiments, R 1 is 4,4-dimethyl- cyclohexyl. In some embodiments, R 1 is 4-methylcyclohexyl. In some embodiments, R 1 is 4-ethyl- cyclohexyl.
  • R 1 is 4-cyclopropylcyclohexyl. In some embodiments, R 1 is optionally substituted norbornanyl. In some embodiments, R 1 is optionally substituted (cycloalkyl)alkyl. In some embodiments, R 1 is bicyclo[2.2.1]heptan-2-ylmethyl. In some embodiments, R 1 is optionally substituted cyclohexylmethyl. In some embodiments, R 1 is cyclohexylmethyl. In some embodiments, R 1 is (4,4-dimethylcyclohexyl)methyl. In some embodiments, R 1 is (4,4-difluorocyclohexyl)methyl.
  • R 1 is optionally substituted heterocyclyl or optionally substituted (heterocyclyl)alkyl. In some embodiments, R 1 is optionally substituted heterocyclyl. In some embodiments, R 1 is optionally substituted tetrahydropyranyl. In some embodiments, R 1 is tetrahydropyran-4-yl. In some embodiments, R 1 is optionally substituted (heterocyclyl)alkyl. In some embodiments, R 1 is optionally substituted tetrahydropyranylmethyl. In some embodiments, R 1 is tetrahydropyran-4-ylmethyl.
  • R 1 is optionally substituted aryl or optionally substituted (aryl)alkyl. In some embodiments, R 1 is optionally substituted (aryl)alkyl. In some embodiments, R 1 is optionally substituted benzyl. In some embodiments, R 1 is 4-methylbenzyl. In some embodiments, R 1 is 4- ethylbenzyl. In some embodiments, R 1 is 4-isopropylbenzyl. In some embodiments, R 1 is 4-(2,2,2-tri- fluoroethyl)benzyl. In some embodiments, R 1 is 4-(l,l-difluoroethyl)benzyl. In some embodiments, R 1 is 4-t-butylbenzyl.
  • R 1 is 4-chlorobenzyl. In some embodiments, R 1 is 4- fluorobenzyl. In some embodiments, R 1 is 4-difluoromethylbenzyl. In some embodiments, R 1 is 4- trifluoromethylbenzyl. In some embodiments, R 1 is 4-difluoromethoxybenzyl. In some embodiments, R 1 is 4-trifluoromethoxybenzyl. In some embodiments, R 1 is 4-methylthiobenzyl. In some embodiments, R 1 is 4-ethylthiobenzyl. In some embodiments, R 1 is 4-methylsulfonylbenzyl. In some embodiments R 1 is 4-ethylsulfonylbenzyl. In some embodiments, R 1 is 4-trifluoromethyl- sulfonylbenzyl.
  • R 1 is optionally substituted heteroaryl or optionally substituted (heteroaryl)alkyl. In some embodiments, R 1 is optionally substituted (heteroaryl)alkyl. In some embodiments, R 1 is optionally substituted (pyridin-2-yl)methyl. In some embodiments, R 1 is optionally (5-chloro-pyridin-2-yl)methyl. In some embodiments, R 1 is optionally (5-methyl-pyridin-2- yl)methyl. In some embodiments, R 1 is optionally substituted (pyridin-3-yl)methyl. In some embodiments, R 1 is (5-methyl-pyridin-3-yl)methyl.
  • Z is 9-membered optionally substituted bicyclic heteroaromatic ring system having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S.
  • Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms, 1 nitrogen ring heteroatom and 1 oxygen ring heteroatom.
  • Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 2 nitrogen ring heteroatoms.
  • Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 3 nitrogen ring heteroatoms.
  • Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 4 nitrogen ring heteroatoms.
  • Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 6-membered heteroaryl are linked to form a 5-membered heterocycle.
  • Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 6-membered heteroaryl having 1 ring nitrogen atom are linked to form a 5- membered heterocycle having 1 oxygen ring atom.
  • Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl are linked to form a 6-membered heterocycle.
  • Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl having 2 or 3 ring nitrogen atoms are linked to form a 6-membered heterocycle having 1 nitrogen ring atom and 1 additional ring heteroatom selected from N and O.
  • Z is one of Formulas Z1-Z33, wherein Z is optionally substituted with 1 or 2 x groups, wherein each R x is attached to a ring carbon atom:
  • each instance of R x independently is -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -OH, -OCH 3 , -OCF 3 or
  • R b is Ci -4 alkyl, C 3 . 4 cycloalkyl, -C(0)-Ci -4 alkyl, -C(0)0-C 1 alkyl or -S(0) 2 -Ci -4 alkyl;
  • R a is Ci_ 4 alkyl, C 3 . 4 cycloalkyl or -S(0) 2 -Ci_ 4 alkyl.
  • Z is Zl, 12, 13, Z4, 15, 16, 17, 111, 112, 113, Z14, Z15, Z16, Z17, Z19, 120, 121, 122, 123, Z24, Z25, Z26, Z27, Z28, Z29 or 130.
  • Z is Z17. In some embodiments, Z is Zll, Z12, Z23 or Z28. In some embodiments, Z is Z3, Z4, 16, 113, 115, 116, 119, 120, 121, 122, Z24, Z25, Z27, Z29 or Z30. In some embodiments, Z is Zl, Z2, 15, 17, 114 or Z26.
  • Z is Z18. In some embodiments, Z is Z8, Z9, Z10, Z31, Z32 or Z33.
  • Z is Zl, Z2, Z3, 15, 16, 17, 125 or Z26. In some embodiments, Z is Zl or Z2.
  • Z is Zl. In some embodiments, Z is Z2.
  • each instance of R x independently is -F, -CI, -CH 3 , -CF 3 or -CN. In some embodiments, each instance of R x independently is -CH 3 or -CF 3 .
  • R a is -CH 3 .
  • R b is -CH 3 .
  • a chemical entity of Formula (I) is a chemical entity of Formula (I I):
  • R 5 , R 6 and R 7 independently are -H, -F, -CI, C1-C4 alkyl, cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , C1-C4 alkoxy, -OCFH 2 , -OCF 2 H, -OCF3, -CN, -N( 2 )( 3 ), -N0 2 , C1-C4 alkylthio, Ci-C 4 alkylsulfonyl or -S(0) 2 CF 3 ; wherein each instance of R 2 and R 3 independently is -H or C1-C4 alkyl, or
  • Z is selected from formulas Z1-Z33, wherein: R x , R a and R b are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
  • a provided chemical entity is a chemical entity of Formula (II), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 .
  • a provided chemical entity is a chemical entity of Formula (II), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH.
  • a provided chemical entity is a chemical entity of Formula (II), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 .
  • a provided chemical entity is a chemical entity of Formula (II), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 ; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26.
  • Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2. [052] in some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein each of 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (II), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 ;
  • Z is Zl, Z2, Z3, Z5, Z6, 11, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a chemical entity of Formula (II) is a chemical entity of Formula (Ila):
  • -C 4 alkyl cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , C C 4 alkoxy, -OCFH 2 , -OCF 2 H, -OCF 3 , -CN, -N(R 2 )(R 3 ), -N0 2 , Ci-C 4 alkylthio, Ci-C 4 alkylsulfonyl or -S(0) 2 CF 3 ; whe H or C1-C4 alkyl, or [055] Designation of the cis configuration indicates that the cis isomer is present in greater amount than the corresponding trans isomer.
  • the cis isomer can be present in a diastereomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the trans isomer.
  • Z is selected from formulas Z1-Z33, wherein: R x , R a and R b are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
  • a provided chemical entity is a chemical entity of Formula (lla), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 .
  • a provided chemical entity is a chemical entity of Formula (lla), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH.
  • a provided chemical entity is a chemical entity of Formula (lla), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 .
  • a provided chemical entity is a chemical entity of Formula (lla), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 ; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (lla), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl.
  • a provided chemical entity is a chemical entity of Formula (lla), wherein: 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 ;
  • Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a chemical entity of Formula (lla) is a chemical entity of Formula (lla-1):
  • R 5 , R 6 and R 7 independently are -H, -F, -CI, Ci-C 4 alkyl, cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , C1-C4 alkoxy, -OCFH 2 , -OCF 2 H, -OCF 3 , -CN, -N(R 2 )(R 3 ), -N0 2 , C C 4 alkylthio, C ⁇ alkylsulfonyl or -S(0) 2 CF 3 ; wherein each instance of R 2 and R 3 independently is -H or C ! -C 4 alkyl,
  • Designation of the (3S,4 ?) configuration indicates that the (3S,4 ?) isomer is present in greater amount than the corresponding (3 ?,4S) isomer.
  • the (3S,4 ?) isomer can be present in an enanteomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the (3 ?,4S) isomer.
  • Z is selected from formulas Z1-Z33, wherein: R x , R a and R b are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, ferf-butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 .
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH.
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 .
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, ferf-butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 ; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl.
  • a provided chemical entity is a chemical entity of Formula (lla-1), wherein: 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 ;
  • Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a chemical entity of Formula (lla) is a chemical entity of Formula (lla-2):
  • R 5 , R 6 and R 7 independently are -H, -F, -CI, Ci-C 4 alkyl, cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , C1-C4 alkoxy, -OCFH 2 , -OCF 2 H, -OCF 3 , -CN, -N(R 2 )(R 3 ), -N0 2 , C C 4 alkylthio, C ⁇ alkylsulfonyl or -S(0) 2 CF 3 ; whe H or C1-C4 alkyl, or
  • Designation of the (3 ?,4S) configuration indicates that the (3 ?,4S) isomer is present in greater amount than the corresponding (3S,4 ?) isomer.
  • the (3 ?,4S) isomer can be present in an enanteomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the (3S,4R) isomer.
  • Z is selected from formulas Z1-Z33, wherein: R x , R a and R b are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, ferf-butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 .
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH.
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 .
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, ferf-butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 ; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl.
  • a provided chemical entity is a chemical entity of Formula (lla-2), wherein: 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 ;
  • Z is Zl, Z2, Z3, Z5, Z6, 11, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a chemical entity of Formula (II) is a chemical entity of Formula (lib):
  • R 5 , R 6 and R 7 independently are -H, -F, -CI, Ci-C 4 alkyl, cyclopropyl, -C ⁇ CH, -CFH 2 , -CF 2 H, -CF 3 , -CF 2 CH 3 , -CH 2 CF 3 , alkoxy, -OCFH 2 , -OCF 2 H, -OCF 3 , -CN, -N(R 2 )(R 3 ), -N0 2 , Ci-C 4 alkylthio, Ci-C 4 alkylsulfonyl or -S(0) 2 CF 3 ; whe H or C1-C4 alkyl, or
  • Z is selected from formulas Z1-Z33, wherein: R x , R a and R b are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
  • a provided chemical entity is a chemical entity of Formula (lib), wherein each of 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 .
  • a provided chemical entity is a chemical entity of Formula (lib), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH.
  • a provided chemical entity is a chemical entity of Formula (Mb), wherein:
  • R 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H,
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 .
  • a provided chemical entity is a chemical entity of Formula (lib), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , isopropyl, tert- butyl, cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -SCH 2 CH 3 , -S(0) 2 CH 3 , -S(0) 2 CH 2 CH 3 or -S(0) 2 CF 3 ; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (lib), wherein each of R 5 , R 6 and R 7 independently is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • a provided chemical entity is a chemical entity of Formula (Mb), wherein: 5 is -H, -F, -CI, -CH 3 , -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CH 3 , -CF 2 CH 3 , -CH 2 CF 3 , cyclopropyl, -OCF 3 , -OCF 2 H, -SCH 3 , -S(0) 2 CH 3 or -C ⁇ CH;
  • R 6 is -H or -F
  • R 7 is -H, -F, -CI or -CH 3 ;
  • Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
  • Glutamate is a fundamental excitatory neurotransmitter in the mammalian brain and central nervous system (CNS). The effects of this endogenous neurotransmitter are mediated through binding to and activation of GLU to glutamate receptors (GLURs), which are broadly classified into metabotropic G-protein coupled (mGluRs) and ligand gated ion channels or ionotropic GluRs.
  • GLURs glutamate receptors
  • the ionotropic GLURs are pharmacologically classified into three main types based on the actions of selective receptor agonists: NMDA (N-methyl D-aspartate selective), KA (kainic acid selective) and AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors whose structure and pharmacological function has been recently reviewed in detail (S. F. Traynelis et al. Pharmacology Reviews, 2010, 62, 405-496). Electrophysiology studies have demonstrated NMDARs to be cation ion channels that are subject to voltage-dependent channel block by endogenous Mg 2+ .
  • NMDARs Activation of NMDARs by glutamate in the presence of glycine as a co-agonist results in opening of the receptor ion channel. This in turn allows for the flow of Na + and Ca 2+ into the cell generating excitatory postsynaptic potentials (EPSPs) and Ca 2+ activated second messenger signaling pathways in neurons. By virtue of their permeability to Ca 2+ , activation of NMDA receptors regulates long-term changes in neuronal communication such as learning and memory and synaptic plasticity. [091] Since the original pharmacological characterization with selective ligands, molecular biology and cloning studies have enabled detailed characterization of NMDARs at the molecular level (Paoletti et al., 2013, Nat. Rev.
  • NMDARs are heterotetramers comprised of two NR1 subunits and two NR2 subunits.
  • NR1 subunits contain the binding site for the glycine co-agonist while NR2 subunits contain the binding site for glutamate.
  • the existence of multiple splice variants for NR1 and four isoforms of NR2 (NR2A, NR2B, NR2C and NR2D) from different genes results in a diverse molecular array and of NMDARs.
  • the pharmacological and electrophysiological properties of NMDARs vary depending on the particular NR1 isoform and NR2 subtype composition.
  • NR2 subtype isoforms are differentially expressed across cell types and brain regions.
  • compounds that interact selectivity with NR2 subunits can exert specific pharmacological effects in particular brain regions and have potential to treat CNS diseases with a high degree of specificity and selectivity (e.g. vz side effects).
  • vz side effects e.g. vz side effects.
  • the low expression of the NR2B subtype in the cerebellum relative to other brain structures indicated lower motor side effects for this subtype.
  • NMDA receptor antagonism has been extensively investigated for its potential to treat a variety of CNS diseases including stroke, epilepsy, pain, depression Parkinson's Disease and Alzheimer's disease (Paoletti et al., Nat. Rev. Neurosci 14:383-400; Sancora, 2008, Nature Rev. Drug Disc, 7, 426- 437).
  • the NMDA receptor offers a number of pharmacological entry points for developing receptor inhibitors.
  • Direct blockers of the NMDAR ion channel pore represent one family of antagonist compounds for which efficacy could be demonstrated in diverse in vitro and in vivo CNS disease models including, epilepsy, pain and neurodegeneration/stroke.
  • compounds from this class as exemplified by phencyclidine (PCP), MK-801, and ketamine, are generally categorized as unselective across the diversity of NMDA receptor subtypes.
  • ketamine has an essentially immediate onset compared to approximately six weeks required for standard serotonin reuptake inhibitor (SSRI) drug therapy.
  • SSRI serotonin reuptake inhibitor
  • intravenous administration of the drug has shown rapid onset and prolonged efficacy that can be maintained with continued intermittent administrations (Zarate et al., 2006, Arch. Gen. Psychiatry 63, 856-864).
  • ketamine has been shown to be effective in cases of depression resistant to standard drug therapies (Murrough et al., 2013, American J. Psychiatry, 170, 1134-1142) including bipolar depression (Zarate et al. 2012, Biol. Psychiatry, 71, 939-946).
  • ketamine therapy is of limited utility and restricted to acute or intermittent administration.
  • orally active selective NMDA antagonists with reduced side effects are needed that can be administered chronically.
  • Ifenprodil a vasodilator a adrenergic antagonist drug, was determined to have a novel allosteric modulator mechanism of action at the NR2B NMDA receptor subtype (Reynolds et al. 1989, Mol. Pharmacol., 36, 758-765). This new mechanism held promise for a new class of NMDA antagonist drugs having therapeutic efficacy without the limiting side effects of subtype unselective ion channel blockers. Following this discovery, NR2B selective antagonist analogs of ifenprodil (Borza et al., 2006, Current Topics in Medicinal Chemistry, 6, 687-695; Layton et al.
  • CP-101,606 has suboptimal pharmacokinetic properties and requires limiting intravenous administration.
  • a slow intravenous infusion protocol was required for optimal results in the aforementioned antidepressant clinical study (Preskorn et al. 2008, Journal of Clinical Psychopharmacology, 28, 631-637).
  • NR2B antagonists including ones that have been subjected to human studies have been described in a review by K.B. Ruppa et al., Annual Reports in Medicinal Chemistry 2012, 47:89-103). These include MK-0657, (Intl. Appl. Publ. No. WO 2004/108705; U.S. Patent No. 7,592,360), EVT-101 and RGH-896.
  • NR2B selective antagonists are needed, as also noted in K.B. Ruppa et al., Annual Reports in Medicinal Chemistry 2012, 47:89-103.
  • NR2B antagonist compounds which are improved in one or more aspects exemplified by pharmacokinetic, absorption, metabolism, excretion (ADME, e.g., oral activity), improved efficacy, off-target activity, improved therapeutic safety index relative and compatibility with chronic oral therapy.
  • NR2B receptor Provided chemical entities are antagonists of the NR2B receptor and have technical advantages with regard to one or more pharmaceutical drug properties, such as oral bioavailability, pharmacokinetic parameters, ADME properties (e.g., CYP inhibition, metabolite formation), in vivo and/or in vitro pharmacological safety.
  • pharmaceutical drug properties such as oral bioavailability, pharmacokinetic parameters, ADME properties (e.g., CYP inhibition, metabolite formation), in vivo and/or in vitro pharmacological safety.
  • a provided chemical entity has NR2B functional NMDA receptor selectivity versus NR2A ("NR2B selectivity", determined as the ratio NR2A IC 50 /NR2B IC 50 , in which the IC 50 values are measured according to the procedure of Example 2.1) > 400.
  • a provided chemical entity has NR2B selectivity > 300.
  • a provided chemical entity has NR2B selectivity > 200.
  • a provided chemical entity has NR2B selectivity > 100.
  • a provided chemical entity has NR2B selectivity > 50.
  • a provided chemical entity has NR2B selectivity > 20.
  • the invention provides a composition comprising a chemical entity of the invention or a pharmaceutically acceptable derivative thereof and a pharmaceutically acceptable carrier, adjuvant, or vehicle.
  • the amount of chemical entity in compositions of this invention is such that is effective to measurably inhibit NR2B, in a biological sample or in a patient.
  • the amount of chemical entity in compositions of this invention is such that is effective to measurably inhibit NR2B, in a biological sample or in a patient.
  • a composition of this invention is formulated for administration to a patient in need of such composition.
  • a composition of this invention is formulated for oral administration to a patient.
  • patient means an animal, preferably a mammal, and most preferably a human.
  • compositions of this invention refers to a non-toxic carrier, adjuvant, or vehicle that does not destroy the pharmacological activity of the chemical entity with which it is formulated.
  • Pharmaceutically acceptable carriers, adjuvants or vehicles that may be used in the compositions of this invention include ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers
  • a "pharmaceutically acceptable derivative” means any non-toxic ester, salt of an ester or other derivative of a chemical entity of this invention (e.g., a prodrug) that, upon administration to a recipient, is capable of providing, either directly or indirectly, a chemical entity of this invention or an inhibitorily active metabolite or residue thereof.
  • inhibitors as used herein, the term "inhibitorily active metabolite or residue thereof" means that a metabolite or residue thereof is also an inhibitor of N 2B.
  • compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir.
  • parenteral as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra- synovial, intrasternal, intrathecal, intrahepatic, intralesional and intracranial injection or infusion techniques.
  • the compositions are administered orally, intraperitoneally or intravenously.
  • Sterile injectable forms of the compositions of this invention may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents.
  • the sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example as a solution in 1,3-butanediol.
  • a non-toxic parenterally acceptable diluent or solvent for example as a solution in 1,3-butanediol.
  • acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution.
  • sterile, fixed oils are conventionally employed as a solvent or suspending medium.
  • any bland fixed oil may be employed including synthetic mono- or di- glycerides.
  • Fatty acids such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions.
  • These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant, such as carboxymethyl cellulose or similar dispersing agents that are commonly used in the formulation of pharmaceutically acceptable dosage forms including emulsions and suspensions.
  • Other commonly used surfactants such as Tweens, Spans and other emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used for the purposes of formulation.
  • compositions of this invention may be orally administered in any orally acceptable dosage form including capsules, tablets, aqueous suspensions or solutions.
  • carriers commonly used include lactose and corn starch.
  • Lubricating agents such as magnesium stearate, are also typically added.
  • useful diluents include lactose and dried cornstarch.
  • aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents may also be added.
  • compositions of this invention may be administered in the form of suppositories for rectal administration.
  • suppositories for rectal administration.
  • suppositories can be prepared by mixing the agent with a suitable non-irritating excipient that is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug.
  • suitable non-irritating excipient include cocoa butter, beeswax and polyethylene glycols.
  • compositions of this invention may also be administered topically, especially when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs.
  • Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topically-transdermal patches may also be used.
  • compositions may be formulated in a suitable ointment containing the active component suspended or dissolved in one or more carriers.
  • Carriers for topical administration of compounds of this invention include mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water.
  • provided pharmaceutically acceptable compositions can be formulated in a suitable lotion or cream containing the active components suspended or dissolved in one or more pharmaceutically acceptable carriers.
  • Suitable carriers include mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
  • compositions may be formulated as micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride.
  • the pharmaceutically acceptable compositions may be formulated in an ointment such as petrolatum.
  • compositions of this invention may also be administered by nasal aerosol or inhalation.
  • Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents.
  • compositions of this invention are formulated for oral administration. Such formulations may be administered with or without food. In some embodiments, pharmaceutically acceptable compositions of this invention are administered without food. In other embodiments, pharmaceutically acceptable compositions of this invention are administered with food.
  • compositions of the present invention that may be combined with the carrier materials to produce a composition in a single dosage form will vary depending upon a variety of factors, including the host treated and the particular mode of administration.
  • provided compositions should be formulated so that a dosage of between 0.01 - 100 mg/kg body weight/day of the inhibitor can be administered to a patient receiving these compositions.
  • a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the judgment of the treating physician and the severity of the particular disease being treated.
  • the amount of a compound of the present invention in the composition will also depend upon the particular compound in the composition.
  • N R2B receptor antagonists [0116] Human therapeutic applications of N R2B receptor antagonists have been summarized in reviews by Traynelis et al. (S. F. Traynelis et al., Pharmacology Reviews, 2010, 62:405-496), Beinat et al. (C. Beinat et al., Current Medicinal Chemistry, 2010, 17:4166-4190) and Mony et al. (L. Mony et al., British J. of Pharmacology, 2009, 157:1301-1317).
  • Antagonism of NR2B can be useful in the treatment of diseases and disorders including depression, pain, Parkinson's disease, Huntington's disease, Alzheimer's disease, cerebral ischaemia, traumatic brain injury, epilepsy and migraine.
  • the activity of a chemical entity utilized in this invention as an antagonist of N R2B or a treatment for a disease or disorder of the central nervous system (CNS) may be assayed in vitro or in vivo.
  • An in vivo assessment of the efficacy of the compounds of the invention may be made using an animal model of a disease or disorder of the CNS, e.g., a rodent or primate model.
  • Cell-based assays may be performed using, e.g., a cell line isolated from a tissue that expresses N R2B, or a cell line that recombinantly expresses NR2B.
  • biochemical or mechanism-based assays e.g., measuring cAM P or cGM P levels, Northern blot, RT-PCR, etc.
  • In vitro assays include assays that determine cell morphology, protein expression, and/or the cytotoxicity, enzyme inhibitory activity, and/or the subsequent functional consequences of treatment of cells with chemical entities of the invention.
  • Alternate in vitro assays quantify the ability of the inhibitor to bind to protein or nucleic acid molecules within the cell. Inhibitor binding may be measured by radiolabelling the inhibitor prior to binding, isolating the inhibitor/target molecule complex and determining the amount of radiolabel bound.
  • inhibitor binding may be determined by running a competition experiment where new inhibitors are incubated with purified proteins or nucleic acids bound to known radioligands.
  • Detailed conditions for assaying a compound utilized in this invention as an antagonist of N 2B are set forth in the Examples below.
  • the aforementioned assays are exemplary and not intended to limit the scope of the invention. A person skilled in the art can appreciate that modifications can be made to conventional assays to develop equivalent assays that obtain the same result.
  • treatment refers to reversing, alleviating, delaying the onset of, or inhibiting the progress of a disease or disorder, or one or more symptoms thereof, as described herein.
  • treatment may be administered after one or more symptoms have developed.
  • treatment may be administered in the absence of symptoms.
  • treatment may be administered to a susceptible individual prior to the onset of symptoms (e.g., in light of a history of symptoms and/or in light of genetic or other susceptibility factors). Treatment may also be continued after symptoms have resolved, for example to prevent or delay their recurrence.
  • compositions may be administered using any amount and any route of administration effective for treating or lessening the severity of a CNS disease or disorder.
  • the chemical entities and compositions, according to the method of the present invention may be administered using any amount and any route of administration effective for treating or lessening the severity of a disease or disorder associated with NR2B.
  • the chemical entities and compositions, according to the method of the present invention may be administered using any amount and any route of administration effective for treating or lessening the severity of a CNS disease or disorder.
  • the disease or disorder is depression with or without concomitant anxiety disorder, e.g., single episode and recurrent depressive disorder, dysthymic disorder, treatment-resistant depression (T D, i.e., major depressive disorder that has not responded to other drug therapies).
  • the disease or disorder is an acute affective disorder, e.g., selected from bipolar disorders including bipolar I and bipolar II manic disorders.
  • the disease or disorder is pain, e.g., selected from pain states arising from a variety of sources including inflammation, nerve damage, diabetic neuropathy and postherpetic neuralgia.
  • the disease or disorder is associated with intractable, such as migraine, fibromyalgia, and trigeminal neuralgia.
  • the disease or disorder is selected from sleep disorders and their sequelae including insomnia, narcolepsy and idiopathic hypersomnia.
  • the disease or disorder is selected from CNS disorders characterized by neuronal hyperexcitablity, such as epilepsy, convulsions and other seizure disorders.
  • the disease or disorder is Parkinson's disease.
  • the disease or disorder is Huntington's disease.
  • the disease or disorder is cognitive dysfunction associated with disorders including schizophrenia, Alzheimer's disease, fronto-temporal dementia, Pick's disease, Lewy body disease, and other senile dementias (e.g., vascular dementia).
  • disorders including schizophrenia, Alzheimer's disease, fronto-temporal dementia, Pick's disease, Lewy body disease, and other senile dementias (e.g., vascular dementia).
  • the present invention provides a method of treating a disorder described herein, comprising administering a chemical entity of the invention in conjunction with one or more pharmaceutical agents.
  • Suitable pharmaceutical agents that may be used in combination with the chemical entities of the present invention include selective serotonin reuptake inhibitors (SSRIs), e.g., in the treatment of depression; dopamine replacement therapy regimens and dopamine agonists, e.g., in the treatment of Parkinson's disease; typical antipsychotics; atypical antipsychotics; anticonvulsants; stimulants; Alzheimer's disease therapies; anti-migraine agents; and anxiolytic agents.
  • SSRIs selective serotonin reuptake inhibitors
  • Suitable SSRIs include citalopram, dapoxetine, escitalopram, fluoxetine, fluvoxamine, indalpine, paroxetine, sertraline, vilazodone and zimelidine.
  • Suitable dopamine replacement therapy regimens include replacement of L-DOPA with a DOPA decarboxylase inhibitor such as carbidopa.
  • Suitable dopamine receptor agonists include aplindore, apomorphine, bromocriptine, cabergoline, ciladopa, dihydroergocryptine, lisuride, pardoprunox, pergolide, piribedil, pramipexole, ropinirole and rotigotine.
  • Suitable typical antipsychotics include chlorpromazine, thioridazine, mesoridazine, levomepromazine, loxapine, molindone, perphenazine, thiothixene, trifluoperazine, haloperidol, fluphenazine, droperidol, zuclopenthixol, flupentixol and prochlorperazine.
  • Suitable atypical antipsychotics include amisulpride, aripiprazole, asenapine, blonanserin, clotiapine, clozapine, iloperidone, llurasidone, mosapramine, olanzapine, paliperidone, perospirone, quetiapine, remoxipride, risperidone, sertindole, sulpiride, ziprasidone, zotepine, bifeprunox, pimavanserin and vabicaserin.
  • Suitable anticonvulsants include carbamazepine, lamotrigine, topiramate and divalproex.
  • Suitable stimulants include Adderall (amphetamine, dextroamphetamine mixed salts), methylphenidate, dextroamphetamine, dexmethylphenidate and lisdexamfetamine.
  • Suitable Alzheimer's disease therapies include acetylcholinesterase inhibitors such as rivastigmine, donepezil, galanthamine and huperazine; alpha-7 nicotinic agonists such as encenicline; and drugs that reduce ⁇ 42 such as BACE inhibitors, gamma secretase modulators and beta amyloid peptide antibodies.
  • acetylcholinesterase inhibitors such as rivastigmine, donepezil, galanthamine and huperazine
  • alpha-7 nicotinic agonists such as encenicline
  • drugs that reduce ⁇ 42 such as BACE inhibitors, gamma secretase modulators and beta amyloid peptide antibodies.
  • Suitable anti-migraine drugs include ergotamine and 5-HT1D agonist triptans such as sumitriptan.
  • Suitable anxiolytic drugs include benzodiazepine receptor modulators such as diazepam, alprazolam, lorazepam and clonazepam.
  • Suitable agents for use in conjunction with a chemical entity of the invention include memantine and modafinil.
  • the exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the infection, the particular agent, its mode of administration, and the like.
  • the chemical entities of the invention are preferably formulated in dosage unit form for ease of administration and uniformity of dosage.
  • dosage unit form refers to a physically discrete unit of agent appropriate for the patient to be treated. It will be understood, however, that the total daily usage of the chemical entities and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment.
  • the specific effective dose level for any particular patient or organism will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific chemical entity employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific chemical entity employed; the duration of the treatment; drugs used in combination or coincidental with the specific chemical entity employed, and like factors well known in the medical arts.
  • patient means an animal, preferably a mammal, and most preferably a human.
  • compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, as an oral or nasal spray, or the like, depending on the severity of the infection being treated.
  • the chemical entities of the invention may be administered orally or parenterally at dosage levels of about 0.01 mg/kg to about 50 mg/kg and preferably from about 1 mg/kg to about 25 mg/kg, of subject body weight per day, one or more times a day, to obtain the desired therapeutic effect.
  • Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs.
  • the liquid dosage forms may contain inert diluents commonly used in the art such as water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.
  • the oral compositions can also include adjuvants such as wetting agents, e
  • Injectable preparations for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents.
  • the sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol.
  • the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S. P. and isotonic sodium chloride solution.
  • sterile, fixed oils are conventionally employed as a solvent or suspending medium.
  • any bland fixed oil can be employed including synthetic mono- or diglycerides.
  • fatty acids such as oleic acid are used in the preparation of injectables.
  • the injectable formulations can be sterilized, for example, by filtration through a bacterial- retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.
  • the rate of chemical entity release can be controlled.
  • biodegradable polymers include poly(orthoesters) and poly(anhydrides).
  • Depot injectable formulations are also prepared by entrapping the chemical entity in liposomes or microemulsions that are compatible with body tissues.
  • compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the chemical entities of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active chemical entity.
  • suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active chemical entity.
  • Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules.
  • the active chemical entity is mixed with at least one inert, pharmaceutically acceptable carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as
  • Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like.
  • the solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner.
  • Examples of embedding compositions that can be used include polymeric substances and waxes.
  • Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polethylene glycols and the like.
  • the active chemical entities can also be in micro-encapsulated form with one or more excipients as noted above.
  • the solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art.
  • the active chemical entity may be admixed with at least one inert diluent such as sucrose, lactose or starch.
  • Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose.
  • additional substances other than inert diluents e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose.
  • the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes.
  • Dosage forms for topical or transdermal administration of a chemical entity of the invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches.
  • the active chemical entity is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required.
  • Ophthalmic formulation, ear drops, and eye drops are also contemplated as being within the scope of the invention.
  • the present invention contemplates the use of transdermal patches, which have the added advantage of providing controlled delivery of a chemical entity to the body.
  • Such dosage forms can be made by dissolving or dispensing the chemical entity in the proper medium.
  • Absorption enhancers can also be used to increase the flux of the chemical entity across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the chemical entity in a polymer matrix or gel.
  • the term “combination,” “combined,” and related terms refers to the simultaneous or sequential administration of therapeutic agents in accordance with this invention.
  • a chemical entity of the present invention may be administered with another therapeutic agent simultaneously or sequentially in separate unit dosage forms or together in a single unit dosage form.
  • the present invention provides a single unit dosage form comprising a chemical entity of Formula (I), an additional therapeutic agent, and a pharmaceutically acceptable carrier, adjuvant, or vehicle.
  • the amount of both, a provided chemical entity and additional therapeutic agent in those compositions which comprise an additional therapeutic agent as described above, that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration.
  • compositions of this invention should be formulated so that a dosage of between 0.01 - 100 mg/kg body weight/day of a provided chemical entity can be administered.
  • compositions which comprise an additional therapeutic agent that additional therapeutic agent and the chemical entity of this invention may act synergistically. Therefore, the amount of additional therapeutic agent in such compositions will be less than that required in a monotherapy utilizing only that therapeutic agent. In such compositions a dosage of between 0.01 - 100 ⁇ g/kg body weight/day of the additional therapeutic agent can be administered.
  • the amount of additional therapeutic agent present in the compositions of this invention will be no more than the amount that would normally be administered in a composition comprising that therapeutic agent as the only active agent.
  • the amount of additional therapeutic agent in the presently disclosed compositions will range from about 50% to 100% of the amount normally present in a composition comprising that agent as the only therapeutically active agent.
  • the present invention provides a medicament comprising at least one chemical entity of Formula (I) and a pharmaceutically acceptable carrier, adjuvant or vehicle.
  • the present invention provides the use of a chemical entity of Formula (I) in the manufacture of a medicament for the treatment of a CNS disease or disorder.
  • LG Br or CI
  • R 1 ' R 1 or Boc leaving group
  • Z is a bicyclic ring system as defined above, and LG is a suitable leaving group for the coupling reaction such chlorine or bromine.
  • the coupling reaction can be conducted as a base-mediated nucleophilic aromatic substitution reaction.
  • the coupling reaction can be conducted as a Buchwald reaction mediated by palladium catalysis.
  • Aromatic substitution coupling reactions can be conducted in suitable protic solvents (e.g., isopropanol, n- butanol) or aprotic solvents (e.g., CH 2 CI 2 , DMF, DMSO, CH 3 CN) solvents at temperatures from ambient to 160 °C, e.g., between 50 °C and 120 °C, with intermediates of formula Z-CI in the presence of a suitable base (e.g., triethylamine, diisopropylethylamine).
  • suitable protic solvents e.g., isopropanol, n- butanol
  • aprotic solvents e.g., CH 2 CI 2 , DMF, DMSO, CH 3 CN
  • Buchwald coupling reactions can be conducted in suitable protic solvents (e.g., n-butanol) or aprotic solvents (e.g., toluene, DMF, DMSO, CH 3 CN) in the presence of a suitable palladium catalyst (e.g., Pd(PPh 3 )) 4 , Brettphos/Brettphos precatalyst) at elevated temperatures from 70 °C to 150 °C, e.g., between 80 °C and 130 °C, with intermediates of formula Z-Br, in the presence of a suitable base (e.g., Cs 2 C0 3 ) under inert atmosphere (e.g., nitrogen).
  • suitable protic solvents e.g., n-butanol
  • aprotic solvents e.g., toluene, DMF, DMSO, CH 3 CN
  • a suitable palladium catalyst e.g., Pd(PPh 3
  • compounds of formula XII are compounds of the invention of formula I.
  • R 1 R 1
  • intermediate compounds of formula XII can be converted to intermediate compounds of formula XIII using deprotection conditions known in the art.
  • R 1 is a t-butyloxycarbonyl (Boc) protecting group
  • intermediate compounds of formula XII can be converted to intermediate compounds of formula XIII using a number of known methods.
  • Boc deprotection is conducted under acidic conditions using either HCI (e.g., 1-4N HCI in ether or dioxane) in a suitable organic solvent (e.g., dichloromethane, methanol or THF) at a temperature between 0 and 50 °C, or using trifluoroacetic acid in an aprotic solvent (e.g,. dichloromethane) at a temperature between 0 °C and room temperature.
  • HCI e.g., 1-4N HCI in ether or dioxane
  • a suitable organic solvent e.g., dichloromethane, methanol or THF
  • trifluoroacetic acid e.g,. dichloromethane
  • aprotic solvent e.g,. dichloromethane
  • Intermediate compounds of formula XIII can be can be converted by one skilled in the art to compounds of the invention of formula I by carbamoylation reaction with a carbamoylating reagent of general Formula R ⁇ CfOjX wherein X is a suitable leaving group (e.g., CI, imidazolyl, hydroxysuccinyl).
  • X is a suitable leaving group (e.g., CI, imidazolyl, hydroxysuccinyl).
  • Reagents of general Formula R ⁇ CfOjX can be implemented in pure isolated form or generated in situ.
  • an alcohol of formula R ⁇ H can be treated with carbonyldiimidazole in an aprotic organic solvent at between 0 °C and room temperature to first form the R ⁇ CiOjimidazolyl carbamoylating reagent.
  • XIV cis (XIV-c/s) or trans (XlV-trans) diastereomeric form as also described by Koudih (Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415).
  • XIV-c/s cis
  • XlV-trans trans diastereomeric form
  • Koudih Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415
  • Suitable leaving groups include sulfonyl leaving groups (e.g., mesylate, triflate, tosylate and nosylate) as well as halide leaving groups (e.g., chloride, bromide and iodide).
  • sulfonates of formula XV may be prepared by treatment of XIV with an appropriate sulfonylchloride (e.g., methanesulfonylchloride as described by Koudih et al.) in a suitable aprotic organic solvent (e.g., dichloromethane, toluene, THF) in the presence of a tertiary amine base (e.g., trimethylamine or diisopropylethylamine) at temperatures from -30 °C to room temperature.
  • an appropriate sulfonylchloride e.g., methanesulfonylchloride as described by Koudih et al.
  • a suitable aprotic organic solvent e.g., dichloromethane, toluene, THF
  • a tertiary amine base e.g., trimethylamine or diisopropylethylamine
  • XlVa XVa e.g., OS0 2 CH 3 , OSO
  • amino group or an amino equivalent group e.g., for an azide amino equivalent group (AE), sodium azide, DMF solvent with heating up to 90 °C, e.g., for direct amine formation, aqueous ammonium hydroxide in a miscible aprotic organic solvent e.g., acetonitrile with heating as needed;
  • conversion of amino equivalent group to an amino group e.g., by catalytic hydrogenation of an azido group with 5% Pd/C in an organic solvent such as ethanol 2]
  • Examples of such amino group equivalents include azido and phthalimido groups.
  • Such amino group equivalents may be introduced by reacting intermediates of formula XV under conditions established in the art.
  • compounds of formula XVI wherein the amine equivalent is an azido group may be prepared by reacting intermediates of formula XV with sodium azide in an aprotic organic solvent (e.g., dimethylformamide) at temperatures ranging from room temperature to 80 °C.
  • aprotic organic solvent e.g., dimethylformamide
  • Compounds of formula XVI wherein the amine equivalent is a phthalimido group can be prepared by standard Gabriel reaction using potassium phthalimide in a suitable solvent at temperatures ranging from room temperature to 120 °C.
  • unmasking the amino group in compounds of formula XVI under known conditions in the art gives the compounds of formula X.
  • compounds of formula XVI wherein the amine equivalent is azide may be unmasked by hydrogenation reaction in an organic solvent in the presence of a 5% palladium on carbon catalyst at room temperature.
  • Phthalimido groups may be unmasked under conditions standard in the art e.g by hydrazinolysis reaction in ethanolic solvent to give compounds of formula X.
  • XW-trans X-trans 3 The individual cis or trans diastereomers of compounds of formula X can be prepared from corresponding pure starting material diastereomers.
  • the 1 group is t-butyl for the Boc-protected intermediate Xa
  • the chromatographic separation of a mixture of XlVa- cis I XlVa-trans isomer starting materials has been described (Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415).
  • the individual cis or trans diasteromers of compounds of formula I, l-c/s and ⁇ -trans can be prepared from corresponding pure X-c/s and X-trans diastereomers using the methods described above and generally represented in Scheme 3.
  • the individual enantiomers of l-c/s and ⁇ -trans racemic mixtures can be prepared by chiral HPLC or other chiral chromatography separation methods known in the art.
  • the individual (3S,4/?)-l-c/s and (3/?,4S)-l-c/s enantiomers and (3S,4S)- ⁇ -trans and (3R,4R)- ⁇ -trans enantiomers of the invention can be prepared from the respective l-c/s and ⁇ -trans racemic mixtures.
  • pure enantiomers of compounds of formula I of the invention can be prepared by using starting materials or intermediates in the methods described above which have sufficiently high chiral purity with respect to the two stereocenters.
  • enantiomer intermediates such as X (e.g., (3S,4/?)-X) and XIV (e.g., (3S,4/?)-XIV) can be implemented in the methods described above to yield enantiomers of formula I (e.g., (3S,4/?)-l).
  • enantiomer intermediates can be prepared by resolution methods or by chiral or asymmetric synthesis methods known in the art.
  • racemic cis or trans intermediate diastereomers of formula X can be resolved into the individual enantiomers by chiral acid addition salt formation and recrystallization (e.g., using a chirally pure tartaric acid) or by formation of an amide with a chiral acid (e.g., an amino acid) followed by standard separation (e.g., by chromatography or recrystallization) and hydrolysis of the of the amide to yield individual enantiomers of formula X.
  • Enantiomer intermediates can also be prepared by asymmetric synthesis. For example the asymmetric hydrogenation of the intermediate XX with chiral catalysts has been described by Krska et. al (Krska S. W.
  • the individual (3/?,4S)-l-c/s enantiomers can be prepared by methods analogous to the above starting from the (3/?,4S)-XXI intermediate prepared by asymmetric hydrogenation of XX using the enantiomeric (S)-(-)-l-[(S)-2-(2'-(diphenylphosphino)phenyl]ferrocenylethyldicyclohexylphosphine (CA number 849925-19-5, available from Solvias as Walphos # SL-W003-2) as the chiral ligand in the hydrogenation catalyst system.
  • a multistep synthesis of intermediate XX has also been described by Krska et al. (Krska W. W. et al Tetrahedron 2009, 65, 8987-8994).
  • the heteroaryl chloride or bromide coupling reagents Z-LG are either commercially available, can be prepared according to known literature procedures for the exact compound or can be prepared using methods known in the art for synthesizing heteroaryl chlorides and bromides.
  • the unsubstituted heteroaryl compound Z can be brominated or chlorinated using methods known in the art (e.g., by treatment with bromine or N-bromosuccinimide or another brominating reagent, or treatment with a chlorinating reagent such as sulfurylchloride).
  • the desired Z-Br or Z-CI heteroaryl coupling reagent can then be isolated by the appropriate procedure (e.g., by chromatography as needed to separate regioisomers).
  • Heteroaryl coupling reagents Z-CI wherein the chloro group is part of an iminochloride substructure can be prepared under standard conditions (e.g., using phosphorus oxychloride at elevated temperature as solvent itself or in a suitable aprotic organic solvent) from the corresponding Z-OH starting material which has the corresponding amido tautomeric substructure.
  • Other heteroaryl coupling reagents can be prepared from the corresponding Z-NH 2 starting material under Sandmeyer reaction type conditions which are well established in the art (i.e., diazotization reaction followed by chlorination or bromination with CuCI or CuBr).
  • the appropriate Z, Z-OH or Z-NH 2 starting materials can be prepared using methods known in the art for synthesizing heteroaryl compounds.
  • a "pure" material is one sufficiently pure for its intended purpose.
  • a diastereomerically pure material means that the desired diastereomer is in a diastereomeric excess of 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the undesired diastereomer(s).
  • an enantiomerically pure or chirally pure material means that the desired enantiomer is in an enantiomeric excess of 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the undesired enantiomer.
  • chemical entities are prepared according to the following procedures. It will be appreciated that, although the general methods depict the synthesis of certain chemical entities of the present invention, the following methods, and other methods known to persons skilled in the art, can be applied to all chemical entities and subclasses and species of each of these chemical entities, as described herein.
  • reaction mixture was then warmed to -10 °C, and H 2 0 (1.1 Kg, 62 mol) was added.
  • Sodium borohydride (234 g, 6.18 mol) was then added in two portions over several minutes at 0 °C with stirring.
  • 6 M HCI (5.6 L) was added over 1 h while maintaining the reaction quenching temperature between 0-25 °C.
  • the reaction mixture was then heated to 40 °C and stirred at this temperature overnight.
  • 6 M NaOH was then slowly added at 0-15 °C to adjust the pH to 12.
  • the aqueous layer was extracted with isopropylacetate (500 m L x 1, 1 L x 3).
  • Step 1 (3S, 4 ?)-tert-butyl 3-fluoro-4-(hydroxymethyl)piperidine-l-carboxylate
  • Step 2 (3S,4 ?)-tert-butyl 3-fluoro-4-((methylsulfonyloxy)methyl)-piperidine-l-carboxylate
  • Step 3 (3S, 4 ?)-tert-butyl 4-(azidomethyl)-3-fluoropiperidine-l-carboxylate
  • Step 4 (3S,4 ?)-tert-butyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate
  • Step 2 N-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine
  • EXAMPLE 1.4a (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-1.3a).
  • EXAMPLE 1.5a (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methylsulfonate (El-1.4a).
  • Step 2 (4-(difluoromethyl)phenyl)methanol
  • a solution of methyl 4-(difluoromethyl)benzoate (1.00 g, 5.37 mmol) in THF (dried) was added dropwise to a stirred suspension of LiAIH 4 in dry THF (25 mL) at 0 °C under N 2 atmosphere.
  • the reaction mixture was stirred for 1 h, then quenched by addition of Na 2 SO 4 .10H 2 O under ice-water bath cooling.
  • the mixture was stirred at rt for 30 min and filtered through celite. The filter mass was washed with EtOAc.
  • EXAMPLE 1.12a (3S,4 ?)-4-ethyl benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate mesylate (El-2.5a).
  • Step 2 (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
  • Step 3 (3S,4R)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
  • EXAMPLE 1.18a (3S,4 ?)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-l.lla).
  • Step 2 (3S,4 ?)-4-chloro-2-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
  • EXAM PLE 1.20a (3S,4 ?)-4-ethyl benzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-6.5a).
  • Step 1 (3S,4/?)-ferf-butyl 3-fluoro-4-((2-(pyridin-2-yl)hydrazinecarboxamido)methyl) piperidine- 1-carboxylate
  • Step 2 (3S, 4/?)-ferf-butyl 4-(([l,2,4]triazolo[4,3-a]pyridin-3-ylamino)methyl)-3-fluoropiperidine- 1-carboxylate
  • Step 3 N-(((3S, 4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]-pyridin-3-amine
  • Step 4 (3S, 4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
  • Step 1 methyl 4-(l,l-difluoroethyl)benzoate
  • Step 3 (3S,4 ?)-4-(l,l-difluoroethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate
  • Step 4 (3S,4R)-4-methylbenzyl 3-fluoro-4-((3-(trifluoromethyl)-[l,2,4]-triazolo[4,3-a]pyrazin-8- ylamino)methyl)piperidine-l-carboxylate
  • EXAMPLE 1.28a (3 ?,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonic acid (E2-1.2a).
  • EXAMPLE 1.30a (3 ?,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (E2-2.2a).
  • Step 1 c/s-4-methylbenzyl 3-fluoro-4-((l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazolo[3,4-d]pyrim- idin-4-ylamino)methyl)piperidine-l-carboxylate
  • Step 2 c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate
  • EXAMPLE 1.31a c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (C-5.1a).
  • Step 2 (3S,4/?)-4-methylbenzyl 3-fluoro-4-((2-(pyridin-2-yl)hydrazinecarboxamido)methyl)- piperidine-l-carboxylate
  • Step 3 (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate
  • EXAMPLE 1.33a (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-6.2a).
  • Step 2 (3S,4/?)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
  • EXAMPLE 1.36a (3S,4/?)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-1.28a).
  • Step 3 6-bromo-2-((trimethylsilyl)ethynyl)pyridin-3-yl acetate
  • Step 2 (3S, 4 ?)-4-methylbenzyl-3-fluoro-4-((l-methyl-l/-/-pyrazolo-[3,4-d]pyrimidin-6-ylamino)- methyl)piperidine-l-carboxylate
  • EXAM PLE 1.40a (3S, 4 ?)-4-methylbenzyl 3-fluoro-4-((l-methyl-lH-pyrazolo-[3,4-d]pyrimidin-6-ylamino)- methyl)piperidine-l-carboxylate methanesulfonate (El-19.26a).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Biomedical Technology (AREA)
  • Neurology (AREA)
  • Neurosurgery (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Psychiatry (AREA)
  • Medicinal Chemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Pain & Pain Management (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Abstract

Disclosed are chemical entities of Formula (I): wherein R1 and Z are defined herein, as NR2B subtype selective receptor antagonists. Also disclosed are pharmaceutical compositions comprising a chemical entity of Formula (I), and methods of treating various diseases and disorders associated with NR2B antagonism, e.g., diseases and disorders of the CNS, such as depression, by administering a chemical entity of Formula (I).

Description

BICYCLIC AZAH ETEROCYCLIC COMPOU NDS AS
NR2B NMDA RECEPTOR ANTAGONISTS
BACKGROUND
[001] Non-selective NMDA receptor antagonists, originally developed in stroke and head trauma, have more recently shown clinical efficacy in treating depression. The non-selective NMDA receptor antagonist, ketamine, has been shown to have rapid onset and efficacy in depression resistant to standard monoamine reuptake inhibitor therapy (Mathews and Zarate, 2013, J. Clin. Psychiatry 74:516-158). However, non-selective NMDA receptor antagonists such as ketamine have a range of undesirable pharmacological activities which limit application in humans. In particular dissociative or psychogenic side effects are particularly prominent for non-selective NMDA receptor antagonists. More recently, N 2B subtype selective NMDA receptor antagonists have demonstrated potential in a wide range of clinical indications. In particular, NR2B antagonists have also demonstrated antidepressant activity in early stage clinical trials (Ibrahim et al., 2012, 7. Clin. Psychopharmacol. 32, 551-557; Preskorn et al., 2008, J. Clin. Psychopharmacol. 28, 631-637). Furthermore, selective NR2B antagonists have advantages over unselective NMDA receptor antagonists such as ketamine due to greatly diminished dissociative side effects. However, NR2B antagonists described to date have generally exhibited drawbacks with regard to other drug properties which have limited potential use in human drug therapy.
SUMMARY
[002] For broad scope of application and safe human use in a range of clinical indications including depression, improved NR2B subtype selective antagonists are needed. The present invention, among other things, addresses the need for NR2B receptor antagonists that are improved in one or more aspects exemplified by pharmacokinetic performance, oral activity, cardiovascular safety, and in vitro and in vivo therapeutic safety index measures.
[003] In some embodiments, the present invention encompasses the insight that chemical entities of Formula (I):
Figure imgf000004_0001
wherein R1 and Z are defined herein, are NR2B subtype selective receptor antagonists. Chemical entities of Formula (I), and pharmaceutically acceptable compositions thereof, are useful for treating a variety of diseases and disorders associated with NR2B receptor antagonism. Such diseases and disorders include those described herein.
BRI EF DESCRI PTION OF TH E DRAWI NG
[004] FIG. 1 shows results of the Forced Swim Test as described in Example 2.2 with the compound El-1.2 ((3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate).
[005] FIG. 2 shows results of the Forced Swim Test as described in Example 2.2 with the compound El-2.2 ((3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate).
DETAI LED DESCRI PTION OF CERTAI N EM BODI M ENTS
General Description of Chemical Entities
[006] In some embodiments, the present invention provides chemical entities of Formula I:
Figure imgf000004_0002
wherein: R1 is alkyl, cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl or (heteroaryl)alkyl, wherein each of cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl and (heteroaryl)alkyl is independently optionally substituted with 1 to 3 groups independently selected from -F, -CI, C C alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, -Q alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, CrC4 alkylthio, Ci-C4 alkylsulfonyl and -S(0)2CF3; whe H or Ci-C4 alkyl, or
Figure imgf000005_0001
Z is 9- or 10-membered bicyclic ring system having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S, wherein said ring system : is a heteroaromatic ring system, which ring system is optionally substituted with 1 or 2 Rx groups and optionally substituted with 1 Ra group, wherein each Rx is attached to a ring carbon atom and Ra is attached to a ring nitrogen atom; or is a 5- or 6-membered heteroaryl in which two adjacent ring atoms are linked to form a 5- or 6- membered heterocycle, which ring system is optionally substituted with 1 or 2 Rx groups and optionally substituted with 1 Rb group, wherein each Rx is attached to a ring carbon atom and Rb is attached to a ring nitrogen atom; wherein: each instance of Rx independently is -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -OH, -OCH3, -OCF3 or
-CN, or two instances of Rx on the same carbon atom together are =0;
Ra is Ci_4 alkyl, C3.4 cycloalkyi or -S(0)2-C!_4 alkyl; and
Rb is Ci_4 alkyl, C3.4 cycloalkyi, -C(0)-Ci_4 alkyl, -C(0)0-Ci_4 alkyl or -S(0)2-Ci_4 alkyl. [007] Unless otherwise specified or clear from context, the term "chemical entity" refers to a compound having the indicated structure, whether in its "free" form (e.g., "free compound" or "free base" or "free acid" form, as applicable), or in a salt form, particularly a pharmaceutically acceptable salt form, and furthermore whether in solid state form or otherwise. In some embodiments, a solid state form is an amorphous (i.e., non-crystalline) form; in some embodiments, a solid state form is a crystalline form. In some embodiments, a crystalline form is a polymorph, pseudohydrate, or hydrate. Similarly, the term encompasses the compound whether provided in solid form or otherwise. Unless otherwise specified, all statements made herein regarding "compounds" apply to the associated chemical entities, as defined.
Chemical Entities and Definitions
[008] Unless otherwise specified, the word "includes" (or any variation thereon, e.g., "include", "including", etc.) is intended to be open-ended. For example, "A includes 1, 2 and 3" means that A includes but is not limited to 1, 2 and 3.
[009] Unless otherwise specified, the phrase "such as" is intended to be open-ended. For example, "A can be a halogen, such as chlorine or bromine" means that A can be, but is not limited to, chlorine or bromine.
[010] Chemical entities of this invention include those described generally above, and are further illustrated by the classes, subclasses, and species disclosed herein. As used herein, the following definitions shall apply unless otherwise indicated. For purposes of this invention, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th Ed., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in Thomas Sorrell, Organic Chemistry, University Science Books, Sausalito, 1999; Smith and March, March's Advanced Organic Chemistry, 5th Edition, John Wiley & Sons, Inc., New York, 2001; Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., New York, 1989; and Carruthers, Some Modern Methods of Organic Synthesis, 3rd Edition, Cambridge University Press, Cambridge, 1987. [Oil] The term "alkyl", used alone or as part of a larger moiety, means a substituted or unsubstituted, linear or branched, univalent hydrocarbon chain that is completely saturated or that contains one or more units of unsaturation. Unless otherwise specified, alkyl groups contain 1 to 7 carbon atoms ("Ci-Cy alkyl"). In some embodiments, alkyl groups contain 1 to 6 carbon atoms ("Ci-Q alkyl"). In some embodiments, alkyl groups contain 1 to 5 carbon atoms ("Ci-Cs alkyl"). In some embodiments, alkyl groups contain 1 to 4 carbon atoms ("Ci-C4 alkyl"). In some embodiments, alkyl groups contain 3 to 7 carbon atoms ("C3-C7 alkyl"). Examples of saturated alkyl groups include methyl, ethyl, n- propyl, i-propyl, n-butyl, t-butyl, i-butyl, s-butyl, homologs and isomers of, for example, n-pentyl, n- hexyl, n-heptyl, n-octyl, and the like. An unsaturated alkyl group is one having one or more carbon- carbon double bonds or carbon-carbon triple bonds. Examples of unsaturated alkyl groups include allyl, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(l,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and the like. The term "lower alkyl" refers to alkyl groups having 1 to 4 (if saturated) or 2 to 4 (if unsaturated) carbon atoms. Exemplary lower alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl and the like. The term "alkenyl" refers to alkyl groups having at least two carbon atoms and at least one carbon-carbon double bond. The term "alkynyl" refers to alkyl groups having at least two carbon atoms and at least one carbon-carbon triple bond.
[012] The term "cycloalkyl", used alone or as part of a larger moiety, e.g., "(cycloalkyl)alkyl", refers to a univalent monocyclic hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic; or bicyclo[2.2.1]heptanyl (also called norbornyl) or bicyclo[2.2.2]octanyl. In some embodiments, cycloalkyl groups contain 3 to 8 ring carbon atoms ("C3-C8 cycloalkyl"). Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1- cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like, as well as bicyclo[2.2.1]heptanyl and bicyclo[2.2.2]octanyl.
[013] The term "alkoxy", used alone or as part of a larger moiety, refers to the group -O-alkyl.
[014] The term "halogen" or "halo", used alone or as part of a larger moiety, refers to fluoro, chloro, bromo or iodo. [015] The term "aryl", used alone or as part of a larger moiety, e.g., "(aryl)alkyl", refers to a univalent monocyclic or bicyclic carbocyclic aromatic ring system. Unless otherwise specified, aryl groups contain 6 or 10 ring members. Examples of aryl include phenyl, naphthyl, and the like.
[016] The term "heteroaryl", used alone or as part of a larger moiety, e.g., "(heteroaryl)alkyl", refers to a univalent monocyclic or bicyclic group having 5 to 10 ring atoms, preferably 5, 6, 9 or 10 ring atoms, having 6, 10, or 14 π electrons shared in a cyclic array, and having, in addition to ring carbon atoms, from one to four ring heteroatoms. Examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, and the like.
[017] The term "heterocyclyl", used alone or as part of a larger moiety, e.g., "(heterocyclyl)alkyl", refers to a univalent stable 5- to 7-membered monocyclic or 7- to 10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated, and having, in addition to ring carbon atoms, one to four heteroatoms. Examples of heterocycyl groups include tetrahydrofuranyl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, and the like.
[018] As used herein, the term "pharmaceutically acceptable salt" refers to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66:1-19, incorporated herein by reference. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like.
[019] Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N+(Ci_4 alkyl)4 salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate and aryl sulfonate.
[020] Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, Z and E double bond isomers, and Z and E conformational isomers. Therefore, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, all tautomeric forms of the compounds of the invention are within the scope of the invention. Additionally, unless otherwise stated, structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures including the replacement hydrogen, carbon, nitrogen, oxygen, chlorine or fluorine with 2H, 3H, nC, 13C, 14C, 13N, 15N, 170, 180, 36CI or 18F, respectively, are within the scope of this invention. Such compounds are useful, for example, as analytical tools, as probes in biological assays, or as therapeutic agents in accordance with the present invention. Additionally, incorporation of heavier isotopes such as deuterium (2H) can afford certain therapeutic advantages resulting from greater metabolic stability, for example, increase in vivo half-life, or reduced dosage requirements.
[021] Diastereomeric excess is expressed as %de, i.e., for diastereomers X and Y, the diastereomeric excess of X = ((x-y)/(x+y))*100, where x and y are the fractions of X and Y, respectively. [022] Enantiomeric excess is expressed as %ee, i.e., for enantiomers X and Y, the entiomeric excess of X = ((x-y)/(x+y))*100, where x and y are the fractions of X and Y, respectively.
Exemplary Embodiments of Chemical Entities
[023] In some embodiments, the present invention provides chemical entities of Formula (I):
Figure imgf000010_0001
wherein R1 and Z are as described above.
[024] In some embodiments, R1 is optionally substituted alkyl.
[025] In some embodiments, R1 is optionally substituted cycloalkyl or optionally substituted (cycloalkyl)alkyl. In some embodiments, R1 is optionally substituted cycloalkyl. In some embodiments, R1 is optionally substituted cyclohexyl. In some embodiments, R1 is cyclohexyl. In some embodiments, R1 is 4,4-difluorocyclohexyl. In some embodiments, R1 is 4,4-dimethyl- cyclohexyl. In some embodiments, R1 is 4-methylcyclohexyl. In some embodiments, R1 is 4-ethyl- cyclohexyl. In some embodiments, R1 is 4-cyclopropylcyclohexyl. In some embodiments, R1 is optionally substituted norbornanyl. In some embodiments, R1 is optionally substituted (cycloalkyl)alkyl. In some embodiments, R1 is bicyclo[2.2.1]heptan-2-ylmethyl. In some embodiments, R1 is optionally substituted cyclohexylmethyl. In some embodiments, R1 is cyclohexylmethyl. In some embodiments, R1 is (4,4-dimethylcyclohexyl)methyl. In some embodiments, R1 is (4,4-difluorocyclohexyl)methyl.
[026] In some embodiments, R1 is optionally substituted heterocyclyl or optionally substituted (heterocyclyl)alkyl. In some embodiments, R1 is optionally substituted heterocyclyl. In some embodiments, R1 is optionally substituted tetrahydropyranyl. In some embodiments, R1 is tetrahydropyran-4-yl. In some embodiments, R1 is optionally substituted (heterocyclyl)alkyl. In some embodiments, R1 is optionally substituted tetrahydropyranylmethyl. In some embodiments, R1 is tetrahydropyran-4-ylmethyl. [027] In some embodiments, R1 is optionally substituted aryl or optionally substituted (aryl)alkyl. In some embodiments, R1 is optionally substituted (aryl)alkyl. In some embodiments, R1 is optionally substituted benzyl. In some embodiments, R1 is 4-methylbenzyl. In some embodiments, R1 is 4- ethylbenzyl. In some embodiments, R1 is 4-isopropylbenzyl. In some embodiments, R1 is 4-(2,2,2-tri- fluoroethyl)benzyl. In some embodiments, R1 is 4-(l,l-difluoroethyl)benzyl. In some embodiments, R1 is 4-t-butylbenzyl. In some embodiments, R1 is 4-chlorobenzyl. In some embodiments, R1 is 4- fluorobenzyl. In some embodiments, R1 is 4-difluoromethylbenzyl. In some embodiments, R1 is 4- trifluoromethylbenzyl. In some embodiments, R1 is 4-difluoromethoxybenzyl. In some embodiments, R1 is 4-trifluoromethoxybenzyl. In some embodiments, R1 is 4-methylthiobenzyl. In some embodiments, R1 is 4-ethylthiobenzyl. In some embodiments, R1 is 4-methylsulfonylbenzyl. In some embodiments R1 is 4-ethylsulfonylbenzyl. In some embodiments, R1 is 4-trifluoromethyl- sulfonylbenzyl.
[028] In some embodiments, R1 is optionally substituted heteroaryl or optionally substituted (heteroaryl)alkyl. In some embodiments, R1 is optionally substituted (heteroaryl)alkyl. In some embodiments, R1 is optionally substituted (pyridin-2-yl)methyl. In some embodiments, R1 is optionally (5-chloro-pyridin-2-yl)methyl. In some embodiments, R1 is optionally (5-methyl-pyridin-2- yl)methyl. In some embodiments, R1 is optionally substituted (pyridin-3-yl)methyl. In some embodiments, R1 is (5-methyl-pyridin-3-yl)methyl.
[029] In some embodiments, Z is 9-membered optionally substituted bicyclic heteroaromatic ring system having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S.
[030] In some embodiments, Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms, 1 nitrogen ring heteroatom and 1 oxygen ring heteroatom.
[031] In some embodiments, Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 2 nitrogen ring heteroatoms.
[032] In some embodiments, Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 3 nitrogen ring heteroatoms. [033] In some embodiments, Z is a 9-membered optionally substituted bicyclic heteraromatic ring system having ring carbon atoms and 4 nitrogen ring heteroatoms.
[034] In some embodiments, Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 6-membered heteroaryl are linked to form a 5-membered heterocycle.
[035] In some embodiments, Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 6-membered heteroaryl having 1 ring nitrogen atom are linked to form a 5- membered heterocycle having 1 oxygen ring atom.
[036] In some embodiments, Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl are linked to form a 6-membered heterocycle.
[037] In some embodiments, Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl having 2 or 3 ring nitrogen atoms are linked to form a 6-membered heterocycle having 1 nitrogen ring atom and 1 additional ring heteroatom selected from N and O.
[038] In some embodiments Z is one of Formulas Z1-Z33, wherein Z is optionally substituted with 1 or 2 x groups, wherein each Rx is attached to a ring carbon atom:
Figure imgf000012_0001
Figure imgf000012_0002
Figure imgf000013_0001
wherein: each instance of Rx independently is -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -OH, -OCH3 , -OCF3 or
-CN, or two instances of Rx on the same carbon atom together are =0;
Rb is Ci-4 alkyl, C3.4 cycloalkyl, -C(0)-Ci-4 alkyl, -C(0)0-C1 alkyl or -S(0)2-Ci-4 alkyl; and
Ra is Ci_4 alkyl, C3.4 cycloalkyl or -S(0)2-Ci_4 alkyl.
[039] In some embodiments, Z is Zl, 12, 13, Z4, 15, 16, 17, 111, 112, 113, Z14, Z15, Z16, Z17, Z19, 120, 121, 122, 123, Z24, Z25, Z26, Z27, Z28, Z29 or 130.
[040] In some embodiments, Z is Z17. In some embodiments, Z is Zll, Z12, Z23 or Z28. In some embodiments, Z is Z3, Z4, 16, 113, 115, 116, 119, 120, 121, 122, Z24, Z25, Z27, Z29 or Z30. In some embodiments, Z is Zl, Z2, 15, 17, 114 or Z26.
[041] In some embodiments, Z is Z18. In some embodiments, Z is Z8, Z9, Z10, Z31, Z32 or Z33.
[042] In some embodiments, Z is Zl, Z2, Z3, 15, 16, 17, 125 or Z26. In some embodiments, Z is Zl or Z2.
In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[043] In some embodiments, each instance of Rx independently is -F, -CI, -CH3, -CF3 or -CN. In some embodiments, each instance of Rx independently is -CH3 or -CF3.
[044] In some embodiments, Ra is -CH3.
[045] In some embodiments, Rb is -CH3.
[046] In some embodiments, a chemical entity of Formula (I) is a chemical entity of Formula (I I):
Figure imgf000014_0001
wherein Z is as described in embodiments of Formula (I), supra, or described in embodiments herein, both singly and in combination; and wherein R5, R6 and R7 independently are -H, -F, -CI, C1-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, C1-C4 alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N( 2)( 3), -N02, C1-C4 alkylthio, Ci-C4 alkylsulfonyl or -S(0)2CF3; wherein each instance of R2 and R3 independently is -H or C1-C4 alkyl, or
Figure imgf000015_0001
[047] In some embodiments, Z is selected from formulas Z1-Z33, wherein: Rx, Ra and Rb are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
[048] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
[049] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
[050] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F; and
R7 is -H, -F, -CI or -CH3.
[051] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2. [052] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein each of 5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[053] In some embodiments, a provided chemical entity is a chemical entity of Formula (II), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F;
R7 is -H, -F, -CI or -CH3; and
Z is Zl, Z2, Z3, Z5, Z6, 11, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[054] In some embodiments, a chemical entity of Formula (II) is a chemical entity of Formula (Ila):
Figure imgf000016_0001
in which the cis configuration denotes relative stereochemistry, i.e., a racemic mixture; wherein Z is as described in embodiments of Formula (I), supra, or described in embodiments herein, both singly and in combination; and wherein R5, R6 and R7 independently are -H, -F, -CI, C!-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, C C4 alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, Ci-C4 alkylthio, Ci-C4 alkylsulfonyl or -S(0)2CF3; whe H or C1-C4 alkyl, or
Figure imgf000016_0002
[055] Designation of the cis configuration indicates that the cis isomer is present in greater amount than the corresponding trans isomer. For example, the cis isomer can be present in a diastereomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the trans isomer.
[056] In some embodiments, Z is selected from formulas Z1-Z33, wherein: Rx, Ra and Rb are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
[057] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
[058] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
[059] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F; and
R7 is -H, -F, -CI or -CH3.
[060] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[061] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2. [062] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla), wherein: 5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F;
R7 is -H, -F, -CI or -CH3; and
Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[063] In some embodiments, a chemical entity of Formula (lla) is a chemical entity of Formula (lla-1):
Figure imgf000018_0001
in which the asterisks (*) denote absolute (3S,4 ?) stereochemistry at the indicated stereocenters; wherein Z is as described in embodiments of Formula (I), supra, or described in embodiments herein, both singly and in combination; and wherein R5, R6 and R7 independently are -H, -F, -CI, Ci-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, C1-C4 alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, C C4 alkylthio, C^ alkylsulfonyl or -S(0)2CF3; wherein each instance of R2 and R3 independently is -H or C!-C4 alkyl, or
Figure imgf000018_0002
[064] Designation of the (3S,4 ?) configuration indicates that the (3S,4 ?) isomer is present in greater amount than the corresponding (3 ?,4S) isomer. For example, the (3S,4 ?) isomer can be present in an enanteomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the (3 ?,4S) isomer. [065] In some embodiments, Z is selected from formulas Z1-Z33, wherein: Rx, Ra and Rb are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
[066] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, ferf-butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
[067] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
[068] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F; and
R7 is -H, -F, -CI or -CH3.
[069] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, ferf-butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[070] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2. [071] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-1), wherein: 5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F;
R7 is -H, -F, -CI or -CH3; and
Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[072] In some embodiments, a chemical entity of Formula (lla) is a chemical entity of Formula (lla-2):
Figure imgf000020_0001
in which the asterisks (*) denote absolute (3 ?,4S) stereochemistry at the indicated stereocenters; wherein Z is as described in embodiments of Formula (I), supra, or described in embodiments herein, both singly and in combination; and wherein R5, R6 and R7 independently are -H, -F, -CI, Ci-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, C1-C4 alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, C C4 alkylthio, C^ alkylsulfonyl or -S(0)2CF3; whe H or C1-C4 alkyl, or
Figure imgf000020_0002
[073] Designation of the (3 ?,4S) configuration indicates that the (3 ?,4S) isomer is present in greater amount than the corresponding (3S,4 ?) isomer. For example, the (3 ?,4S) isomer can be present in an enanteomeric excess of 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the (3S,4R) isomer. [074] In some embodiments, Z is selected from formulas Z1-Z33, wherein: Rx, Ra and Rb are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination.
[075] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, ferf-butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
[076] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
[077] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F; and
R7 is -H, -F, -CI or -CH3.
[078] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, ferf-butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[079] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2. [080] In some embodiments, a provided chemical entity is a chemical entity of Formula (lla-2), wherein: 5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F;
R7 is -H, -F, -CI or -CH3; and
Z is Zl, Z2, Z3, Z5, Z6, 11, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[081] In some embodiments, a chemical entity of Formula (II) is a chemical entity of Formula (lib):
Figure imgf000022_0001
in which the c/'s configuration denotes relative stereochemistry, i.e., a racemic mixture; wherein Z is as described in embodiments of Formula (I), supra, or described in embodiments herein, both singly and in combination; and wherein R5, R6 and R7 independently are -H, -F, -CI, Ci-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, Ci-C4 alkylthio, Ci-C4 alkylsulfonyl or -S(0)2CF3; whe H or C1-C4 alkyl, or
Figure imgf000022_0002
[082] In some embodiments, Z is selected from formulas Z1-Z33, wherein: Rx, Ra and Rb are as described in embodiments of formulas Z1-Z33, supra, or described in embodiments herein, both singly and in combination. [083] In some embodiments, a provided chemical entity is a chemical entity of Formula (lib), wherein each of 5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
[084] In some embodiments, a provided chemical entity is a chemical entity of Formula (lib), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
[085] In some embodiments, a provided chemical entity is a chemical entity of Formula (Mb), wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F; and
R7 is -H, -F, -CI or -CH3.
[086] In some embodiments, a provided chemical entity is a chemical entity of Formula (lib), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, tert- butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3; and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[087] In some embodiments, a provided chemical entity is a chemical entity of Formula (lib), wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH and Z is Zl, Z2, Z3, Z5, Z6, Z7, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[088] In some embodiments, a provided chemical entity is a chemical entity of Formula (Mb), wherein: 5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH;
R6 is -H or -F;
R7 is -H, -F, -CI or -CH3; and
Z is Zl, 12, 13, 15, 16, 17, Z25 or Z26. In some embodiments, Z is Zl or Z2. In some embodiments, Z is Zl. In some embodiments, Z is Z2.
[089] Exemplary chemical entities of Formula (I) are shown in Tables l.C, l.El and 1.E2, below.
Table l.C
Figure imgf000024_0001
(racemic)
Figure imgf000024_0002
Table l.C
Figure imgf000025_0001
(racemic)
Figure imgf000025_0002
Table l.C
Figure imgf000026_0001
(racemic)
Figure imgf000026_0002
Table l.C
Figure imgf000027_0001
(racemic)
Figure imgf000027_0002
Table l.C
Figure imgf000028_0001
(racemic)
Figure imgf000028_0002
Table l.C
Figure imgf000029_0001
(racemic)
Figure imgf000029_0002
Table l.C
Figure imgf000030_0001
(racemic)
Figure imgf000030_0002
Table l.C
Figure imgf000031_0001
(racemic)
Figure imgf000031_0002
Table l.C
Figure imgf000032_0001
(racemic)
Figure imgf000032_0002
Table l.C
Figure imgf000033_0001
(racemic)
Figure imgf000033_0002
Table l.C
Figure imgf000034_0001
(racemic)
Figure imgf000034_0002
Table l.C
Figure imgf000035_0001
(racemic)
Figure imgf000035_0002
Table l.C
Figure imgf000036_0001
(racemic)
Figure imgf000036_0002
Table l.C
Figure imgf000037_0001
(racemic)
Figure imgf000037_0002
Table l.C
Figure imgf000038_0001
(racemic)
Figure imgf000038_0002
Table l.C
Figure imgf000039_0001
(racemic)
Figure imgf000039_0002
Table l.C
Figure imgf000040_0001
(racemic)
Figure imgf000040_0002
Table l.C
Figure imgf000041_0001
(racemic)
Figure imgf000041_0002
Table l.C
Figure imgf000042_0001
(racemic)
Figure imgf000042_0002
Table l.C
Figure imgf000043_0001
(racemic)
Figure imgf000043_0002
Table l.C
Figure imgf000044_0001
(racemic)
Figure imgf000044_0002
Table l.C
Figure imgf000045_0001
(racemic)
Figure imgf000045_0002
Table l.C
Figure imgf000046_0001
(racemic)
Figure imgf000046_0002
Table l.C
Figure imgf000047_0001
(racemic)
Figure imgf000047_0002
Table l.C
Figure imgf000048_0001
(racemic)
Figure imgf000048_0002
Table l.C
Figure imgf000049_0001
(racemic)
Figure imgf000049_0002
Table l.C
Figure imgf000050_0001
(racemic)
Figure imgf000050_0002
Table l.C
Figure imgf000051_0001
(racemic)
Figure imgf000051_0002
Table l.C
Figure imgf000052_0001
(racemic)
Figure imgf000052_0002
Table l.C
Figure imgf000053_0001
(racemic)
Figure imgf000053_0002
Table l.C
Figure imgf000054_0001
(racemic)
Figure imgf000054_0002
Table l.C
Figure imgf000055_0001
(racemic)
Figure imgf000055_0002
Table l.C
Figure imgf000056_0001
(racemic)
Figure imgf000056_0003
Table 1.E1
Figure imgf000056_0002
Figure imgf000056_0004
Table 1.E1
Figure imgf000057_0001
Figure imgf000057_0002
Table 1.E1
Figure imgf000058_0001
Figure imgf000058_0002
Table 1.E1
Figure imgf000059_0001
Figure imgf000059_0002
Table 1.E1
Figure imgf000060_0001
Figure imgf000060_0002
Table 1.E1
Figure imgf000061_0001
Figure imgf000061_0002
Table 1.E1
Figure imgf000062_0001
Figure imgf000062_0002
Table 1.E1
Figure imgf000063_0001
Figure imgf000063_0002
Table 1.E1
Figure imgf000064_0001
Figure imgf000064_0002
Table 1.E1
Figure imgf000065_0001
Figure imgf000065_0002
Table 1.E1
Figure imgf000066_0001
Figure imgf000066_0002
Table 1.E1
Figure imgf000067_0001
Figure imgf000067_0002
Table 1.E1
Figure imgf000068_0001
Figure imgf000068_0002
Table 1.E1
Figure imgf000069_0001
Figure imgf000069_0002
Table 1.E1
Figure imgf000070_0001
Figure imgf000070_0002
Table 1.E1
Figure imgf000071_0001
Figure imgf000071_0002
Table 1.E1
Figure imgf000072_0001
Figure imgf000072_0002
Table 1.E1
Figure imgf000073_0001
Figure imgf000073_0002
Table 1.E1
Figure imgf000074_0001
Figure imgf000074_0002
Table 1.E1
Figure imgf000075_0001
Figure imgf000075_0002
Table 1.E1
Figure imgf000076_0001
Figure imgf000076_0002
Table 1.E1
Figure imgf000077_0001
Figure imgf000077_0002
Table 1.E1
Figure imgf000078_0001
Figure imgf000078_0002
Table 1.E1
Figure imgf000079_0001
Figure imgf000079_0002
Table 1.E1
Figure imgf000080_0001
Figure imgf000080_0002
Table 1.E1
Figure imgf000081_0001
Figure imgf000081_0002
Table 1.E1
Figure imgf000082_0001
Figure imgf000082_0002
Table 1.E1
Figure imgf000083_0001
Figure imgf000083_0002
Table 1.E1
Figure imgf000084_0001
Figure imgf000084_0002
Table 1.E1
Figure imgf000085_0001
Figure imgf000085_0002
Table 1.E1
Figure imgf000086_0001
Figure imgf000086_0002
Table 1.E1
Figure imgf000087_0001
Figure imgf000087_0002
Table 1.E1
Figure imgf000088_0001
Figure imgf000088_0002
Table 1.E2
Figure imgf000089_0001
Figure imgf000089_0002
Table 1.E2
Figure imgf000090_0001
Figure imgf000090_0002
Table 1.E2
Figure imgf000091_0001
Figure imgf000091_0002
Table 1.E2
Figure imgf000092_0001
Figure imgf000092_0002
Table 1.E2
Figure imgf000093_0001
Figure imgf000093_0002
Table 1.E2
Figure imgf000094_0001
Figure imgf000094_0002
Table 1.E2
Figure imgf000095_0001
Figure imgf000095_0002
Table 1.E2
Figure imgf000096_0001
Figure imgf000096_0002
Table 1.E2
Figure imgf000097_0001
Figure imgf000097_0002
Table 1.E2
Figure imgf000098_0001
Figure imgf000098_0002
Table 1.E2
Figure imgf000099_0001
Figure imgf000099_0002
Table 1.E2
Figure imgf000100_0001
Figure imgf000100_0002
Table 1.E2
Figure imgf000101_0001
Figure imgf000101_0002
Table 1.E2
Figure imgf000102_0001
Figure imgf000102_0002
Table 1.E2
Figure imgf000103_0001
Figure imgf000103_0002
Table 1.E2
Figure imgf000104_0001
Figure imgf000104_0002
Table 1.E2
Figure imgf000105_0001
Figure imgf000105_0002
Table 1.E2
Figure imgf000106_0001
Figure imgf000106_0002
Table 1.E2
Figure imgf000107_0001
Figure imgf000107_0002
Table 1.E2
Figure imgf000108_0001
Figure imgf000108_0002
Table 1.E2
Figure imgf000109_0001
Figure imgf000109_0002
Table 1.E2
Figure imgf000110_0001
Figure imgf000110_0002
Table 1.E2
Figure imgf000111_0001
Figure imgf000111_0002
Table 1.E2
Figure imgf000112_0001
Figure imgf000112_0002
Table 1.E2
Figure imgf000113_0001
Figure imgf000113_0002
Table 1.E2
Figure imgf000114_0001
Figure imgf000114_0002
Table 1.E2
Figure imgf000115_0001
Figure imgf000115_0002
Table 1.E2
Figure imgf000116_0001
Figure imgf000116_0002
Table 1.E2
Figure imgf000117_0001
Figure imgf000117_0002
Table 1.E2
Figure imgf000118_0001
Figure imgf000118_0002
Table 1.E2
Figure imgf000119_0001
Figure imgf000119_0002
Table 1.E2
Figure imgf000120_0001
Figure imgf000120_0002
Table 1.E2
Figure imgf000121_0001
Figure imgf000121_0002
Phormocology
[090] Glutamate (GLU) is a fundamental excitatory neurotransmitter in the mammalian brain and central nervous system (CNS). The effects of this endogenous neurotransmitter are mediated through binding to and activation of GLU to glutamate receptors (GLURs), which are broadly classified into metabotropic G-protein coupled (mGluRs) and ligand gated ion channels or ionotropic GluRs. The ionotropic GLURs are pharmacologically classified into three main types based on the actions of selective receptor agonists: NMDA (N-methyl D-aspartate selective), KA (kainic acid selective) and AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors whose structure and pharmacological function has been recently reviewed in detail (S. F. Traynelis et al. Pharmacology Reviews, 2010, 62, 405-496). Electrophysiology studies have demonstrated NMDARs to be cation ion channels that are subject to voltage-dependent channel block by endogenous Mg2+. Activation of NMDARs by glutamate in the presence of glycine as a co-agonist results in opening of the receptor ion channel. This in turn allows for the flow of Na+ and Ca2+ into the cell generating excitatory postsynaptic potentials (EPSPs) and Ca2+ activated second messenger signaling pathways in neurons. By virtue of their permeability to Ca2+, activation of NMDA receptors regulates long-term changes in neuronal communication such as learning and memory and synaptic plasticity. [091] Since the original pharmacological characterization with selective ligands, molecular biology and cloning studies have enabled detailed characterization of NMDARs at the molecular level (Paoletti et al., 2013, Nat. Rev. Neurosci. 14:383-400). Thus, NMDARs are heterotetramers comprised of two NR1 subunits and two NR2 subunits. NR1 subunits contain the binding site for the glycine co-agonist while NR2 subunits contain the binding site for glutamate. The existence of multiple splice variants for NR1 and four isoforms of NR2 (NR2A, NR2B, NR2C and NR2D) from different genes results in a diverse molecular array and of NMDARs. The pharmacological and electrophysiological properties of NMDARs vary depending on the particular NR1 isoform and NR2 subtype composition. Furthermore, the NR2 subtype isoforms are differentially expressed across cell types and brain regions. Thus, compounds that interact selectivity with NR2 subunits can exert specific pharmacological effects in particular brain regions and have potential to treat CNS diseases with a high degree of specificity and selectivity (e.g. vz side effects). For example the low expression of the NR2B subtype in the cerebellum relative to other brain structures (Cull-Candy et al., 1998, Neuropharmacol. 37:1369- 1380) indicated lower motor side effects for this subtype.
[092] NMDA receptor antagonism has been extensively investigated for its potential to treat a variety of CNS diseases including stroke, epilepsy, pain, depression Parkinson's Disease and Alzheimer's disease (Paoletti et al., Nat. Rev. Neurosci 14:383-400; Sancora, 2008, Nature Rev. Drug Disc, 7, 426- 437). The NMDA receptor offers a number of pharmacological entry points for developing receptor inhibitors. Direct blockers of the NMDAR ion channel pore represent one family of antagonist compounds for which efficacy could be demonstrated in diverse in vitro and in vivo CNS disease models including, epilepsy, pain and neurodegeneration/stroke. However, compounds from this class, as exemplified by phencyclidine (PCP), MK-801, and ketamine, are generally categorized as unselective across the diversity of NMDA receptor subtypes.
Figure imgf000122_0001
MK801 (dizocilpine) Ketamine Phencyclidine (PCP) [093] In humans unselective, high-affinity NMDA antagonists have generally been associated with serious clinical side effects including hallucinations, dysphoria and lack of coordination. Nevertheless, ketamine, an intravenous drug originally approved for use in anesthesia (Haas et. al, 1992, Anesthesia Prog., 39, 61-68) has more recently demonstrated clinical efficacy as an antidepressant therapy (Katalinic et al. 2013, Aust. N. Z. J. Psychiatry, 47, 710-727). The antidepressant action of acute ketamine therapy has an essentially immediate onset compared to approximately six weeks required for standard serotonin reuptake inhibitor (SSRI) drug therapy. Thus, intravenous administration of the drug has shown rapid onset and prolonged efficacy that can be maintained with continued intermittent administrations (Zarate et al., 2006, Arch. Gen. Psychiatry 63, 856-864). Finally, ketamine has been shown to be effective in cases of depression resistant to standard drug therapies (Murrough et al., 2013, American J. Psychiatry, 170, 1134-1142) including bipolar depression (Zarate et al. 2012, Biol. Psychiatry, 71, 939-946). However, as an intravenous drug with serious side effects (Gianni et. al 1985, Psychiatric Medicine, 3, 197-217; Curran et al 2000, Addiction, 95, 575-590) and potential chronic toxicity (Hardy et al., 2012, J. Clin. Oncol. 30:3611-3617; Noppers et al., 2011, Pain 152:2173-2178) ketamine therapy is of limited utility and restricted to acute or intermittent administration. To have broader scope of application and utility as a therapy for depression and other CNS diseases, orally active selective NMDA antagonists with reduced side effects are needed that can be administered chronically.
[094] Ifenprodil, a vasodilator a adrenergic antagonist drug, was determined to have a novel allosteric modulator mechanism of action at the NR2B NMDA receptor subtype (Reynolds et al. 1989, Mol. Pharmacol., 36, 758-765). This new mechanism held promise for a new class of NMDA antagonist drugs having therapeutic efficacy without the limiting side effects of subtype unselective ion channel blockers. Following this discovery, NR2B selective antagonist analogs of ifenprodil (Borza et al., 2006, Current Topics in Medicinal Chemistry, 6, 687-695; Layton et al. Current Topics in Medicinal Chemistry, 6, 697-709) optimized against the undesirable a adrenergic activity included Ro-25,6981 (Fischer et al. 1997, 7. Pharmacol. Exp. Ther., 283, 1285-1292) and CP-101,606 otherwise known as traxoprodil (Chenard et al. 1995, Journal of Medicinal Chemistry, 38, 3138-3145; Menniti et al. 1998, CNS Drug Reviews., 4, 307-322). In a clinical study, CP-101,606 evidenced antidepressant activity in humans after intravenous administration with a favorable dissociative side effect profile relative to unselective NMDA antagonists (Preskorn et al. 2008, Journal of Clinical Psychopharmacology, 28, 631-637). However, CP-101,606 has suboptimal pharmacokinetic properties and requires limiting intravenous administration. For CP-101,606 a slow intravenous infusion protocol was required for optimal results in the aforementioned antidepressant clinical study (Preskorn et al. 2008, Journal of Clinical Psychopharmacology, 28, 631-637).
Figure imgf000124_0001
ifenprodil Ro-25,6981 CP-101 ,606 ] Other NR2B antagonists including ones that have been subjected to human studies have been described in a review by K.B. Ruppa et al., Annual Reports in Medicinal Chemistry 2012, 47:89-103). These include MK-0657, (Intl. Appl. Publ. No. WO 2004/108705; U.S. Patent No. 7,592,360), EVT-101 and RGH-896.
Figure imgf000124_0002
EVT101 MK0657 RGH-896 [096] For broad scope of application and safe human use, improved NR2B selective antagonists are needed, as also noted in K.B. Ruppa et al., Annual Reports in Medicinal Chemistry 2012, 47:89-103. There is a need for NR2B antagonist compounds which are improved in one or more aspects exemplified by pharmacokinetic, absorption, metabolism, excretion (ADME, e.g., oral activity), improved efficacy, off-target activity, improved therapeutic safety index relative and compatibility with chronic oral therapy. For example, drug-related systolic as well as diastolic blood pressure elevation cardiovascular side effect for MK0657 after oral dosing have been described in a published clinical efficacy trial study in patients with Parkinson's Disease (Addy et al., J. Clin. Pharm. 2009, v49:856-864). Similar blood pressure effects were reported to have also been observed after single doses of MK0657 in safety studies with healthy elderly subjects.
[097] Provided chemical entities are antagonists of the NR2B receptor and have technical advantages with regard to one or more pharmaceutical drug properties, such as oral bioavailability, pharmacokinetic parameters, ADME properties (e.g., CYP inhibition, metabolite formation), in vivo and/or in vitro pharmacological safety.
[098] In some embodiments, a provided chemical entity has NR2B functional NMDA receptor selectivity versus NR2A ("NR2B selectivity", determined as the ratio NR2A IC50/NR2B IC50, in which the IC50 values are measured according to the procedure of Example 2.1) > 400. In some embodiments, a provided chemical entity has NR2B selectivity > 300. In some embodiments, a provided chemical entity has NR2B selectivity > 200. In some embodiments, a provided chemical entity has NR2B selectivity > 100. In some embodiments, a provided chemical entity has NR2B selectivity > 50. In some embodiments, a provided chemical entity has NR2B selectivity > 20.
Uses, Formulation and Administration, and Pharmaceutically Acceptable Compositions
[099] In some embodiments, the invention provides a composition comprising a chemical entity of the invention or a pharmaceutically acceptable derivative thereof and a pharmaceutically acceptable carrier, adjuvant, or vehicle. The amount of chemical entity in compositions of this invention is such that is effective to measurably inhibit NR2B, in a biological sample or in a patient. In some embodiments, the amount of chemical entity in compositions of this invention is such that is effective to measurably inhibit NR2B, in a biological sample or in a patient. In some embodiments, a composition of this invention is formulated for administration to a patient in need of such composition. In some embodiments, a composition of this invention is formulated for oral administration to a patient.
[0100] The term "patient," as used herein, means an animal, preferably a mammal, and most preferably a human.
[0101] The term "pharmaceutically acceptable carrier, adjuvant, or vehicle" refers to a non-toxic carrier, adjuvant, or vehicle that does not destroy the pharmacological activity of the chemical entity with which it is formulated. Pharmaceutically acceptable carriers, adjuvants or vehicles that may be used in the compositions of this invention include ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat.
[0102] A "pharmaceutically acceptable derivative" means any non-toxic ester, salt of an ester or other derivative of a chemical entity of this invention (e.g., a prodrug) that, upon administration to a recipient, is capable of providing, either directly or indirectly, a chemical entity of this invention or an inhibitorily active metabolite or residue thereof.
[0103] As used herein, the term "inhibitorily active metabolite or residue thereof" means that a metabolite or residue thereof is also an inhibitor of N 2B.
[0104] Compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term "parenteral" as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra- synovial, intrasternal, intrathecal, intrahepatic, intralesional and intracranial injection or infusion techniques. Preferably, the compositions are administered orally, intraperitoneally or intravenously. Sterile injectable forms of the compositions of this invention may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium.
[0105] For this purpose, any bland fixed oil may be employed including synthetic mono- or di- glycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant, such as carboxymethyl cellulose or similar dispersing agents that are commonly used in the formulation of pharmaceutically acceptable dosage forms including emulsions and suspensions. Other commonly used surfactants, such as Tweens, Spans and other emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used for the purposes of formulation.
[0106] Pharmaceutically acceptable compositions of this invention may be orally administered in any orally acceptable dosage form including capsules, tablets, aqueous suspensions or solutions. In the case of tablets for oral use, carriers commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried cornstarch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents may also be added.
[0107] Alternatively, pharmaceutically acceptable compositions of this invention may be administered in the form of suppositories for rectal administration. These can be prepared by mixing the agent with a suitable non-irritating excipient that is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax and polyethylene glycols.
[0108] Pharmaceutically acceptable compositions of this invention may also be administered topically, especially when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs.
[0109] Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topically-transdermal patches may also be used.
[0110] For topical applications, provided pharmaceutically acceptable compositions may be formulated in a suitable ointment containing the active component suspended or dissolved in one or more carriers. Carriers for topical administration of compounds of this invention include mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. Alternatively, provided pharmaceutically acceptable compositions can be formulated in a suitable lotion or cream containing the active components suspended or dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
[0111] For ophthalmic use, provided pharmaceutically acceptable compositions may be formulated as micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride. Alternatively, for ophthalmic uses, the pharmaceutically acceptable compositions may be formulated in an ointment such as petrolatum.
[0112] Pharmaceutically acceptable compositions of this invention may also be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents.
[0113] Most preferably, pharmaceutically acceptable compositions of this invention are formulated for oral administration. Such formulations may be administered with or without food. In some embodiments, pharmaceutically acceptable compositions of this invention are administered without food. In other embodiments, pharmaceutically acceptable compositions of this invention are administered with food.
[0114] The amount of compounds of the present invention that may be combined with the carrier materials to produce a composition in a single dosage form will vary depending upon a variety of factors, including the host treated and the particular mode of administration. Preferably, provided compositions should be formulated so that a dosage of between 0.01 - 100 mg/kg body weight/day of the inhibitor can be administered to a patient receiving these compositions.
[0115] It should also be understood that a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the judgment of the treating physician and the severity of the particular disease being treated. The amount of a compound of the present invention in the composition will also depend upon the particular compound in the composition.
Uses of Chemical Entities and Pharmaceutically Acceptable Compositions
[0116] Human therapeutic applications of N R2B receptor antagonists have been summarized in reviews by Traynelis et al. (S. F. Traynelis et al., Pharmacology Reviews, 2010, 62:405-496), Beinat et al. (C. Beinat et al., Current Medicinal Chemistry, 2010, 17:4166-4190) and Mony et al. (L. Mony et al., British J. of Pharmacology, 2009, 157:1301-1317). Antagonism of NR2B can be useful in the treatment of diseases and disorders including depression, pain, Parkinson's disease, Huntington's disease, Alzheimer's disease, cerebral ischaemia, traumatic brain injury, epilepsy and migraine.
[0117] The activity of a chemical entity utilized in this invention as an antagonist of N R2B or a treatment for a disease or disorder of the central nervous system (CNS) may be assayed in vitro or in vivo. An in vivo assessment of the efficacy of the compounds of the invention may be made using an animal model of a disease or disorder of the CNS, e.g., a rodent or primate model. Cell-based assays may be performed using, e.g., a cell line isolated from a tissue that expresses N R2B, or a cell line that recombinantly expresses NR2B. Additionally, biochemical or mechanism-based assays, e.g., measuring cAM P or cGM P levels, Northern blot, RT-PCR, etc., may be performed. In vitro assays include assays that determine cell morphology, protein expression, and/or the cytotoxicity, enzyme inhibitory activity, and/or the subsequent functional consequences of treatment of cells with chemical entities of the invention. Alternate in vitro assays quantify the ability of the inhibitor to bind to protein or nucleic acid molecules within the cell. Inhibitor binding may be measured by radiolabelling the inhibitor prior to binding, isolating the inhibitor/target molecule complex and determining the amount of radiolabel bound. Alternatively, inhibitor binding may be determined by running a competition experiment where new inhibitors are incubated with purified proteins or nucleic acids bound to known radioligands. Detailed conditions for assaying a compound utilized in this invention as an antagonist of N 2B are set forth in the Examples below. The aforementioned assays are exemplary and not intended to limit the scope of the invention. A person skilled in the art can appreciate that modifications can be made to conventional assays to develop equivalent assays that obtain the same result.
[0118] As used herein, the terms "treatment," "treat," and "treating" refer to reversing, alleviating, delaying the onset of, or inhibiting the progress of a disease or disorder, or one or more symptoms thereof, as described herein. In some embodiments, treatment may be administered after one or more symptoms have developed. In other embodiments, treatment may be administered in the absence of symptoms. For example, treatment may be administered to a susceptible individual prior to the onset of symptoms (e.g., in light of a history of symptoms and/or in light of genetic or other susceptibility factors). Treatment may also be continued after symptoms have resolved, for example to prevent or delay their recurrence.
[0119] The chemical entities and compositions, according to the method of the present invention, may be administered using any amount and any route of administration effective for treating or lessening the severity of a CNS disease or disorder.
[0120] In some embodiments, the chemical entities and compositions, according to the method of the present invention, may be administered using any amount and any route of administration effective for treating or lessening the severity of a disease or disorder associated with NR2B.
[0121] In some embodiments, the chemical entities and compositions, according to the method of the present invention, may be administered using any amount and any route of administration effective for treating or lessening the severity of a CNS disease or disorder. [0122] In some embodiments, the disease or disorder is depression with or without concomitant anxiety disorder, e.g., single episode and recurrent depressive disorder, dysthymic disorder, treatment-resistant depression (T D, i.e., major depressive disorder that has not responded to other drug therapies).
[0123] In some embodiments, the disease or disorder is an acute affective disorder, e.g., selected from bipolar disorders including bipolar I and bipolar II manic disorders.
[0124] In some embodiments, the disease or disorder is pain, e.g., selected from pain states arising from a variety of sources including inflammation, nerve damage, diabetic neuropathy and postherpetic neuralgia. In some embodiments, the disease or disorder is associated with intractable, such as migraine, fibromyalgia, and trigeminal neuralgia.
[0125] In some embodiments, the disease or disorder is selected from sleep disorders and their sequelae including insomnia, narcolepsy and idiopathic hypersomnia.
[0126] In some embodiments, the disease or disorder is selected from CNS disorders characterized by neuronal hyperexcitablity, such as epilepsy, convulsions and other seizure disorders.
[0127] In some embodiments, the disease or disorder is Parkinson's disease.
[0128] In some embodiments, the disease or disorder is Huntington's disease.
[0129] In some embodiments, the disease or disorder is cognitive dysfunction associated with disorders including schizophrenia, Alzheimer's disease, fronto-temporal dementia, Pick's disease, Lewy body disease, and other senile dementias (e.g., vascular dementia).
[0130] In some embodiments, the present invention provides a method of treating a disorder described herein, comprising administering a chemical entity of the invention in conjunction with one or more pharmaceutical agents. Suitable pharmaceutical agents that may be used in combination with the chemical entities of the present invention include selective serotonin reuptake inhibitors (SSRIs), e.g., in the treatment of depression; dopamine replacement therapy regimens and dopamine agonists, e.g., in the treatment of Parkinson's disease; typical antipsychotics; atypical antipsychotics; anticonvulsants; stimulants; Alzheimer's disease therapies; anti-migraine agents; and anxiolytic agents.
[0131] Suitable SSRIs include citalopram, dapoxetine, escitalopram, fluoxetine, fluvoxamine, indalpine, paroxetine, sertraline, vilazodone and zimelidine.
[0132] Suitable dopamine replacement therapy regimens include replacement of L-DOPA with a DOPA decarboxylase inhibitor such as carbidopa.
[0133] Suitable dopamine receptor agonists include aplindore, apomorphine, bromocriptine, cabergoline, ciladopa, dihydroergocryptine, lisuride, pardoprunox, pergolide, piribedil, pramipexole, ropinirole and rotigotine.
[0134] Suitable typical antipsychotics include chlorpromazine, thioridazine, mesoridazine, levomepromazine, loxapine, molindone, perphenazine, thiothixene, trifluoperazine, haloperidol, fluphenazine, droperidol, zuclopenthixol, flupentixol and prochlorperazine.
[0135] Suitable atypical antipsychotics include amisulpride, aripiprazole, asenapine, blonanserin, clotiapine, clozapine, iloperidone, llurasidone, mosapramine, olanzapine, paliperidone, perospirone, quetiapine, remoxipride, risperidone, sertindole, sulpiride, ziprasidone, zotepine, bifeprunox, pimavanserin and vabicaserin.
[0136] Suitable anticonvulsants include carbamazepine, lamotrigine, topiramate and divalproex.
[0137] Suitable stimulants include Adderall (amphetamine, dextroamphetamine mixed salts), methylphenidate, dextroamphetamine, dexmethylphenidate and lisdexamfetamine.
[0138] Suitable Alzheimer's disease therapies include acetylcholinesterase inhibitors such as rivastigmine, donepezil, galanthamine and huperazine; alpha-7 nicotinic agonists such as encenicline; and drugs that reduce Αβ42 such as BACE inhibitors, gamma secretase modulators and beta amyloid peptide antibodies.
[0139] Suitable anti-migraine drugs include ergotamine and 5-HT1D agonist triptans such as sumitriptan. [0140] Suitable anxiolytic drugs include benzodiazepine receptor modulators such as diazepam, alprazolam, lorazepam and clonazepam.
[0141] Other suitable agents for use in conjunction with a chemical entity of the invention include memantine and modafinil.
[0142] The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the infection, the particular agent, its mode of administration, and the like. The chemical entities of the invention are preferably formulated in dosage unit form for ease of administration and uniformity of dosage. The expression "dosage unit form" as used herein refers to a physically discrete unit of agent appropriate for the patient to be treated. It will be understood, however, that the total daily usage of the chemical entities and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment. The specific effective dose level for any particular patient or organism will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific chemical entity employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific chemical entity employed; the duration of the treatment; drugs used in combination or coincidental with the specific chemical entity employed, and like factors well known in the medical arts. The term "patient", as used herein, means an animal, preferably a mammal, and most preferably a human.
[0143] The pharmaceutically acceptable compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, as an oral or nasal spray, or the like, depending on the severity of the infection being treated. In certain embodiments, the chemical entities of the invention may be administered orally or parenterally at dosage levels of about 0.01 mg/kg to about 50 mg/kg and preferably from about 1 mg/kg to about 25 mg/kg, of subject body weight per day, one or more times a day, to obtain the desired therapeutic effect.
[0144] Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.
[0145] Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S. P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.
[0146] The injectable formulations can be sterilized, for example, by filtration through a bacterial- retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.
[0147] In order to prolong the effect of a chemical entity of the present invention, it is often desirable to slow the absorption of the chemical entity from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the chemical entity then depends upon its rate of dissolution that, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered chemical entity form is accomplished by dissolving or suspending the chemical entity in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the chemical entity in biodegradable polymers such as polylactide- polyglycolide. Depending upon the ratio of chemical entity to polymer and the nature of the particular polymer employed, the rate of chemical entity release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the chemical entity in liposomes or microemulsions that are compatible with body tissues.
[0148] Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the chemical entities of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active chemical entity.
[0149] Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules.
In such solid dosage forms, the active chemical entity is mixed with at least one inert, pharmaceutically acceptable carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.
[0150] Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polethylene glycols and the like. [0151] The active chemical entities can also be in micro-encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active chemical entity may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes.
[0152] Dosage forms for topical or transdermal administration of a chemical entity of the invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active chemical entity is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation, ear drops, and eye drops are also contemplated as being within the scope of the invention. Additionally, the present invention contemplates the use of transdermal patches, which have the added advantage of providing controlled delivery of a chemical entity to the body. Such dosage forms can be made by dissolving or dispensing the chemical entity in the proper medium. Absorption enhancers can also be used to increase the flux of the chemical entity across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the chemical entity in a polymer matrix or gel.
[0153] As used herein, the term "combination," "combined," and related terms refers to the simultaneous or sequential administration of therapeutic agents in accordance with this invention. For example, a chemical entity of the present invention may be administered with another therapeutic agent simultaneously or sequentially in separate unit dosage forms or together in a single unit dosage form. Accordingly, the present invention provides a single unit dosage form comprising a chemical entity of Formula (I), an additional therapeutic agent, and a pharmaceutically acceptable carrier, adjuvant, or vehicle. [0154] The amount of both, a provided chemical entity and additional therapeutic agent (in those compositions which comprise an additional therapeutic agent as described above), that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Preferably, compositions of this invention should be formulated so that a dosage of between 0.01 - 100 mg/kg body weight/day of a provided chemical entity can be administered.
[0155] In those compositions which comprise an additional therapeutic agent, that additional therapeutic agent and the chemical entity of this invention may act synergistically. Therefore, the amount of additional therapeutic agent in such compositions will be less than that required in a monotherapy utilizing only that therapeutic agent. In such compositions a dosage of between 0.01 - 100 μg/kg body weight/day of the additional therapeutic agent can be administered.
[0156] The amount of additional therapeutic agent present in the compositions of this invention will be no more than the amount that would normally be administered in a composition comprising that therapeutic agent as the only active agent. Preferably the amount of additional therapeutic agent in the presently disclosed compositions will range from about 50% to 100% of the amount normally present in a composition comprising that agent as the only therapeutically active agent.
[0157] In some embodiments, the present invention provides a medicament comprising at least one chemical entity of Formula (I) and a pharmaceutically acceptable carrier, adjuvant or vehicle.
[0158] In some embodiments, the present invention provides the use of a chemical entity of Formula (I) in the manufacture of a medicament for the treatment of a CNS disease or disorder.
General synthetic methods
[0159] Chemical entities of Formula (I) can be synthesized according to Scheme 1 and/or using methods known in the art. Scheme 1
Figure imgf000138_0001
LG = Br or CI
R1 ' = R1 or Boc leaving group
Figure imgf000138_0002
I XIII a. base (e.g. diisopropylethylamine), organic solvent (e.g. n-butanol), heat or Buchwald coupling conditions b. Boc cleavage conditions (e.g. CF3C02H or HCI, room temperature) when 1' = Boc c.carbamate formation conditions e.g. carbonyldiimidazole, R^OH, DMSO, room temperature 0] In the method depicted in Scheme 1, in a first step, compounds of formula XII can be prepared by coupling intermediates of general formula X, wherein R1 = R1 or a protecting group such as Boc (t-butyloxycarbonyl), with intermediates Z-LG of general formula XI. For compounds of general formula XI, Z is a bicyclic ring system as defined above, and LG is a suitable leaving group for the coupling reaction such chlorine or bromine. In certain cases the coupling reaction can be conducted as a base-mediated nucleophilic aromatic substitution reaction. In certain cases the coupling reaction can be conducted as a Buchwald reaction mediated by palladium catalysis. Aromatic substitution coupling reactions can be conducted in suitable protic solvents (e.g., isopropanol, n- butanol) or aprotic solvents (e.g., CH2CI2, DMF, DMSO, CH3CN) solvents at temperatures from ambient to 160 °C, e.g., between 50 °C and 120 °C, with intermediates of formula Z-CI in the presence of a suitable base (e.g., triethylamine, diisopropylethylamine). Buchwald coupling reactions can be conducted in suitable protic solvents (e.g., n-butanol) or aprotic solvents (e.g., toluene, DMF, DMSO, CH3CN) in the presence of a suitable palladium catalyst (e.g., Pd(PPh3))4, Brettphos/Brettphos precatalyst) at elevated temperatures from 70 °C to 150 °C, e.g., between 80 °C and 130 °C, with intermediates of formula Z-Br, in the presence of a suitable base (e.g., Cs2C03) under inert atmosphere (e.g., nitrogen). In the case where R1 = R1, compounds of formula XII are compounds of the invention of formula I. In the case where R1 is a protecting group, then intermediate compounds of formula XII can be converted to intermediate compounds of formula XIII using deprotection conditions known in the art. For example when R1 is a t-butyloxycarbonyl (Boc) protecting group, intermediate compounds of formula XII can be converted to intermediate compounds of formula XIII using a number of known methods. Typically the Boc deprotection is conducted under acidic conditions using either HCI (e.g., 1-4N HCI in ether or dioxane) in a suitable organic solvent (e.g., dichloromethane, methanol or THF) at a temperature between 0 and 50 °C, or using trifluoroacetic acid in an aprotic solvent (e.g,. dichloromethane) at a temperature between 0 °C and room temperature. The latter is particularly relevant for compounds which are sensitive to chloride-mediated side reactions. Intermediate compounds of formula XIII can be can be converted by one skilled in the art to compounds of the invention of formula I by carbamoylation reaction with a carbamoylating reagent of general Formula R^CfOjX wherein X is a suitable leaving group (e.g., CI, imidazolyl, hydroxysuccinyl). Reagents of general Formula R^CfOjX can be implemented in pure isolated form or generated in situ. For example, an alcohol of formula R^H can be treated with carbonyldiimidazole in an aprotic organic solvent at between 0 °C and room temperature to first form the R^CiOjimidazolyl carbamoylating reagent. In situ reaction of the R^CiOjimidazolyl carbamoylating reagent with intermediate compounds of formula XIII (in free base or acid addition salt form, at temperatures between 0 °C and 70 °C ) in an aprotic solvent (e.g., DMSO) yields compounds of the invention of formula I. 1] Intermediates of general formula X can be prepared as depicted in Scheme 2 wherein the R1 group is t-butyl for the Boc-protected intermediate Xa as described by Koudih (Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415) in a method that is also applicable to diverse R1 groups of the compounds of the invention. The synthesis starts from compound XIV which is available in pure cis (XIV-c/s) or trans (XlV-trans) diastereomeric form as also described by Koudih (Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415). In the first step the hydroxyl group of XIV is converted to a suitable leaving group to give compounds of general formula XV. Suitable leaving groups include sulfonyl leaving groups (e.g., mesylate, triflate, tosylate and nosylate) as well as halide leaving groups (e.g., chloride, bromide and iodide). Reaction conditions for these conversions are well established in the art, Thus, for example sulfonates of formula XV may be prepared by treatment of XIV with an appropriate sulfonylchloride (e.g., methanesulfonylchloride as described by Koudih et al.) in a suitable aprotic organic solvent (e.g., dichloromethane, toluene, THF) in the presence of a tertiary amine base (e.g., trimethylamine or diisopropylethylamine) at temperatures from -30 °C to room temperature. Intermediates of formula XV can then be converted directly to the compounds of formula Xa by direct amination reaction under conditions established in the art (e.g., by reaction with aqueous ammonium hydroxide in a suitable organic cosolvent such as acetonitrile) or indirectly via an intermediate of formula XVI bearing a masked or protected amino group equivalent.
Scheme 2
Figure imgf000140_0001
= leaving group
XlVa XVa e.g., OS02CH3, OSO
Figure imgf000140_0002
= amino group equivalent e.g., N3, phthalimide
Xa XVIa a. Conversion of hydroxyl group to a suitable leaving group, e.g., for LG = a trifluorosulfonate leaving group, (CF3S02)20, diisopropylethylamine, aprotic organic solvent (e.g. acetonitrile) at -20 °C to room temperature; b. conversion of the leaving group to an amino group or an amino equivalent group, e.g., for an azide amino equivalent group (AE), sodium azide, DMF solvent with heating up to 90 °C, e.g., for direct amine formation, aqueous ammonium hydroxide in a miscible aprotic organic solvent e.g., acetonitrile with heating as needed; c. conversion of amino equivalent group to an amino group, e.g., by catalytic hydrogenation of an azido group with 5% Pd/C in an organic solvent such as ethanol 2] Examples of such amino group equivalents include azido and phthalimido groups. Such amino group equivalents may be introduced by reacting intermediates of formula XV under conditions established in the art. For example, compounds of formula XVI wherein the amine equivalent is an azido group may be prepared by reacting intermediates of formula XV with sodium azide in an aprotic organic solvent (e.g., dimethylformamide) at temperatures ranging from room temperature to 80 °C. Compounds of formula XVI wherein the amine equivalent is a phthalimido group can be prepared by standard Gabriel reaction using potassium phthalimide in a suitable solvent at temperatures ranging from room temperature to 120 °C. In a final step, unmasking the amino group in compounds of formula XVI under known conditions in the art gives the compounds of formula X. For example compounds of formula XVI wherein the amine equivalent is azide may be unmasked by hydrogenation reaction in an organic solvent in the presence of a 5% palladium on carbon catalyst at room temperature. Phthalimido groups may be unmasked under conditions standard in the art e.g by hydrazinolysis reaction in ethanolic solvent to give compounds of formula X.
Scheme 3
Figure imgf000142_0001
Figure imgf000142_0002
XW-trans X-trans 3] The individual cis or trans diastereomers of compounds of formula X can be prepared from corresponding pure starting material diastereomers. For example in the case where the 1 group is t-butyl for the Boc-protected intermediate Xa, the chromatographic separation of a mixture of XlVa- cis I XlVa-trans isomer starting materials has been described (Koudih et al. Eur. J. Med. Chem. 2012, 53, 408-415). In turn, the individual cis or trans diasteromers of compounds of formula I, l-c/s and \-trans, can be prepared from corresponding pure X-c/s and X-trans diastereomers using the methods described above and generally represented in Scheme 3. The individual enantiomers of l-c/s and \-trans racemic mixtures can be prepared by chiral HPLC or other chiral chromatography separation methods known in the art. In this manner the individual (3S,4/?)-l-c/s and (3/?,4S)-l-c/s enantiomers and (3S,4S)-\-trans and (3R,4R)-\-trans enantiomers of the invention can be prepared from the respective l-c/s and \-trans racemic mixtures. Alternatively, pure enantiomers of compounds of formula I of the invention can be prepared by using starting materials or intermediates in the methods described above which have sufficiently high chiral purity with respect to the two stereocenters. For example, enantiomer intermediates such as X (e.g., (3S,4/?)-X) and XIV (e.g., (3S,4/?)-XIV) can be implemented in the methods described above to yield enantiomers of formula I (e.g., (3S,4/?)-l). In turn, enantiomer intermediates can be prepared by resolution methods or by chiral or asymmetric synthesis methods known in the art. For example, racemic cis or trans intermediate diastereomers of formula X can be resolved into the individual enantiomers by chiral acid addition salt formation and recrystallization (e.g., using a chirally pure tartaric acid) or by formation of an amide with a chiral acid (e.g., an amino acid) followed by standard separation (e.g., by chromatography or recrystallization) and hydrolysis of the of the amide to yield individual enantiomers of formula X. 4] Enantiomer intermediates can also be prepared by asymmetric synthesis. For example the asymmetric hydrogenation of the intermediate XX with chiral catalysts has been described by Krska et. al (Krska S. W. et al Tetrahedron 2009, 65, 8987-8994) to give intermediates of high enantiomeric purity which can be used to prepare (3S,4/?)-l-c/s and (3/?,4S)-l-c/s enantiomers. As described by Krska et al. and detailed in the experimental procedures provided herein, hydrogenation of XX using the chiral asymmetric hydrogenation catalyst system comprised of (R)-(-)-l-[(R)-2-(2'-(diphenyl- phosphino)phenyl]ferrocenylethyldicyclohexylphosphine (CA number 388079-60-5, commercially available from Solvias as Walphos # SL-W003-1) and cycloctadiene rhodium chloride dimer [(COD)RhCI]2 yields hydrogenation product (3S,4/?)-XXI of high chiral purity (Scheme 4). The asymmetric synthesis of (3S,4/?)-XIV intermediates follows from intermediate (3S,4/?)-XXI by removal of the benzyl group by catalytic hydrogenation followed by carbamoylation reaction to introduce the -CO2 1 or -CO2R1 (e.g., Boc) group (Scheme 4). In turn, the individual (3S,4/?)-l-c/s enantiomers can be prepared from (3S,4/?)-XIV intermediates using the methods described above (Schemes 1-3). Further, we have conducted a single crystal X-ray structure determination of a synthetic derivative of (3S,4/?)-XXI. This study supports assignment of the (3S,4 ?) absolute stereochemistry for (3S,4/?)-XIV and (3S,4/?)-l-c/s enantiomers prepared from it.
Scheme 4
Figure imgf000144_0001
Figure imgf000144_0002
(3S, 4R)-X (3S, 4R)-XIV a. ( )-(-)-l-[( )-2-(2'-(diphenylphosphino)phenyl]ferrocenylethyldicyclohexylphosphine,
[(COD)RhCI]2, H2, 300 psi, MeOH; b. H2, 10% Pd/C, 6N HCI, MeOH, atmospheric pressure;
c. carbonyldiimidazole, R^OH, DMSO, room temperature
[0165] The individual (3/?,4S)-l-c/s enantiomers can be prepared by methods analogous to the above starting from the (3/?,4S)-XXI intermediate prepared by asymmetric hydrogenation of XX using the enantiomeric (S)-(-)-l-[(S)-2-(2'-(diphenylphosphino)phenyl]ferrocenylethyldicyclohexylphosphine (CA number 849925-19-5, available from Solvias as Walphos # SL-W003-2) as the chiral ligand in the hydrogenation catalyst system. A multistep synthesis of intermediate XX has also been described by Krska et al. (Krska W. W. et al Tetrahedron 2009, 65, 8987-8994).
[0166] The heteroaryl chloride or bromide coupling reagents Z-LG are either commercially available, can be prepared according to known literature procedures for the exact compound or can be prepared using methods known in the art for synthesizing heteroaryl chlorides and bromides. For example, the unsubstituted heteroaryl compound Z can be brominated or chlorinated using methods known in the art (e.g., by treatment with bromine or N-bromosuccinimide or another brominating reagent, or treatment with a chlorinating reagent such as sulfurylchloride). The desired Z-Br or Z-CI heteroaryl coupling reagent can then be isolated by the appropriate procedure (e.g., by chromatography as needed to separate regioisomers). Heteroaryl coupling reagents Z-CI wherein the chloro group is part of an iminochloride substructure can be prepared under standard conditions (e.g., using phosphorus oxychloride at elevated temperature as solvent itself or in a suitable aprotic organic solvent) from the corresponding Z-OH starting material which has the corresponding amido tautomeric substructure. Other heteroaryl coupling reagents can be prepared from the corresponding Z-NH2 starting material under Sandmeyer reaction type conditions which are well established in the art (i.e., diazotization reaction followed by chlorination or bromination with CuCI or CuBr). In some cases, the appropriate Z, Z-OH or Z-NH2 starting materials can be prepared using methods known in the art for synthesizing heteroaryl compounds.
[0167] As used in the above general synthetic methods, a "pure" material is one sufficiently pure for its intended purpose. For example, a diastereomerically pure material means that the desired diastereomer is in a diastereomeric excess of 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the undesired diastereomer(s). Similarly, an enantiomerically pure or chirally pure material means that the desired enantiomer is in an enantiomeric excess of 60%, 70%, 80%, 85%, 90%, 92%, 94%, 96% or 98% relative to the undesired enantiomer.
EXAM PLES
EXAMPLE 1. Chemical Entities.
[0168] As depicted in the Examples below, in certain exemplary embodiments, chemical entities are prepared according to the following procedures. It will be appreciated that, although the general methods depict the synthesis of certain chemical entities of the present invention, the following methods, and other methods known to persons skilled in the art, can be applied to all chemical entities and subclasses and species of each of these chemical entities, as described herein.
[0169] Temperatures are given in degrees centigrade. If not mentioned otherwise, all evaporations are performed under reduced pressure, preferably between 15 mm Hg and 100 mm Hg. The structures of intermediates and final products are confirmed by standard analytical methods, for example, mass spectrometry and NM spectroscopy. Enanteomeric excess can be determined via chiral HPLC method (CHIRALPAK AD-H4.6*150mm, 5μη% mobile phase: hexane/EtOH = 65/35, flow rate = 1.5mL/min). Abbreviations: aq Aqueous
BINAP 2,2'-Bis(diphenylphosphino)-l,l'-binaphthalene
Boc t-butoxycarbonyl
Brettphos 2-(dicyclohexylphosphino)3,6-dimethoxy-2',4',6'-triisopropyl- Ι,Γ-biphenyl
Brettphos precatalyst chloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2',4', 6'- triisopropyl-l,l'-biphenyl][2-(2-aminoethyl)phenyl]- palladium(ll)
nBuOH n-butanol
Cbz Benzyloxycarbonyl
CDI Carbonyldiimidazole
DAST diethylamino sulfur trifluoride
dba Dibenylideneacetone
DCM Dichloromethane
DCE 1,2-dichloroethane
DIPEA N,N-diisopropylethylamine
DMF N,N-dimethylformamide
DMSO dimethyl sulfoxide
Et Ethyl
Et20 diethyl ether ("ether")
EtOAc ethyl acetate
EtOH Ethanol
eq Equivalents
h Hours
HPLC high performance liquid chromatography
LC liquid chromatography
Me Methyl
Ms Methanesulfonyl
MsCI Methanesulfonylchloride MS mass spectrometry
MS (ESI) mass spectrometry electrospray ionization
NM P N-methyl-2-pyrrolidone
NM nuclear magnetic resonance
PEG polyethylene glycol
rt room temperature
Tf Triflate
Tf20 triflic anhydride
TFAA trifluoroacetic anhydride
THF Tetrahydrofuran
TLC thin layer chromatography
Ts p-toluenesulfonyl
EXAMPLE l.A. (3S,4/?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride.
Figure imgf000147_0001
HCI
Step 1. (3-fluoropyridin-4-yl)methanol
Figure imgf000147_0002
[0171] A mechanically stirred solution of 3-fluoropyridine (600 g, 6.18 mol) in dry THF (6 L) was cooled to -65 °C under N2 atmosphere. Lithium diisopropylamine solution in THF (3.4 L, 6.5 mol) was added over 2 hours while keeping the temperature below -60 °C, and the reaction mixture was allowed to stir an additional hour below -60 °C. Neat DMF (804 mL, 10.4 mol) was then added over a one hour period at a rate as to maintain the temperature below -60 °C. The reaction mixture was monitored by TLC for the complete consumption of 3-fluoropyridine starting material. Upon completion, the reaction mixture was then warmed to -10 °C, and H20 (1.1 Kg, 62 mol) was added. Sodium borohydride (234 g, 6.18 mol) was then added in two portions over several minutes at 0 °C with stirring. Then 6 M HCI (5.6 L) was added over 1 h while maintaining the reaction quenching temperature between 0-25 °C. The reaction mixture was then heated to 40 °C and stirred at this temperature overnight. To the mixture 6 M NaOH was then slowly added at 0-15 °C to adjust the pH to 12. The aqueous layer was extracted with isopropylacetate (500 m L x 1, 1 L x 3). The combined organic layers were washed with brine, dried over Na2S04 and concentrated in vacuo. To the crude product was added heptane-isopropylacetate (1.2 L, v/v = 5/1), and the mixture was stirred at 0 °C for 30 min. The product crystallized as a pale-yellow solid during stirring. The mixture was filtered, the filter cake was extracted with cooled heptane (250 m L x 1), collected and dried under vacuum to give the title compound as a pale-yellow solid (688 g, 88%). 1H N M R (400 M Hz, CDCI3) δ 8.42 (d, J = 4.8 Hz, 1H), 8.40 (d, J = 1.6 Hz, 1H), 7.49 (t, J = 4.8 Hz, 1H), 4.85 (s, 2H), 2.35 (br s, 1H).
Step 2. l-benzyl-3-fluoro-4-(hydroxymethyl)pyridin-l-ium bromide
Figure imgf000148_0001
Br 2] To a stirred solution of (3-fluoropyridin-4-yl)methanol(688 g, 5.40 mol) in acetone (6.8 L) was added neat BnBr (1018 g, 5.90 mol). The resulting mixture was stirred overnight at reflux. The reaction mixture was cooled to room temperature and diluted with heptane (1 L). The suspension was filtered, and the wet cake was then stirred with 25% acetone/heptane v/v (3 L) and filtered. The filter mass was then dried in vacuo to afford the title compound as a pale-yellow solid (1570 g, 97%). *H NM R (400 M Hz, CD3OD) δ 8.97 (d, J = 6.4 Hz, 1H), 8.28 (t, J = 6.4 Hz, 1H), 7.57-7.52 (m, 2H), 7.53- 7.48 (m, 3H), 5.85 (s, 2H), 4.96 (s, 2H).
Step 3. (l-benzyl-5-fluoro-l,2,3,6-tetrahydropyridin-4-yl)methanol hydrochloride
Figure imgf000149_0001
HCI
[0173] To the stirred solution of l-benzyl-3-fluoro-4-(hydroxymethyl)pyridin-l-ium bromide (1.55 Kg, 5.19 mol) in methanol (8.0 L) was added NaBH4 (296 g, 7.82 mol) portionwise while maintaining the reaction temperature at ca. 0 °C, followed by addition of water (16.0 L) while maintaining the reaction temperature below 0 °C. The mixture was allowed to warm to room temperature. The aqueous layer was extracted with isopropylacetate (2.0 L x 3), and the combined organic phases were dried and concentrated in vacuo. The residue was dissolved in 5% methanol in isopropylacetate (2.0 L). The solution was warmed to 50 °C, followed by addition of a solution of 4 M HCI in dioxane (1.43 L). The resulting mixture allowed to room temperature, and stirred overnight. The precipitate was collected by filtration, washed with 5% methanol-isopropylacetate (2.0 L), heptane (1.5 L) and dried under vacuum. The crude product was dissolved in 50% methanol- isopropyl (14.0 L), and charcoal (255 g) was added. The resulting mixture was heated to reflux, and stirred for 2 hours. Then the suspension was filtered through celite. The filter cake was extracted with 20% methanol-isopropylacetate (6.0 L). The filtrate was collected and concentrated to roughly 25% of its original volume and the solid precipitate was isolated by filtration. The solid was extracted with 5% methanol-isopropylacetate (4.0 L), and dried overnight under vacuum to afford the title compound as an off-white solid (1.08 Kg, 81 %).1H NMR (400 MHz, CD3OD) δ 7.61 (br s, 2H), 7.51 (br m, 3H), 4.47 (br s, 2H), 4.21 (br s, 2H), 3.84 (br s, 2H), 3.36 (br s, 2H), 2.59 (br s, 2H).
Step 4. ((3S,4/?)-l-benzyl-3-fluoropiperdin-4-yl)methanol
Figure imgf000149_0002
[0174] Under N2 atmosphere, a three-necked round-bottom flask was charged with 180 mg of (R)-(-)-l- [(R)-2-(2'-(diphenylphosphino)phenyl]ferrocenylethyldicyclohexylphosphine (CA number 388079- 60-5, commercially available from Solvias as Walphos # SL-W003-1), 60 mg of cycloctadiene rhodium chloride dimer [(COD)RhCI]2 (purchased from Aldrich Chemistry) and dry nitrogen degassed dichloromethane (10 mL). The solution was stirred at ambient temperature for 45 min. A solution of (l-benzyl-5-fluoro-l,2,3,6-tetrahydropyridin-4-yl)methanol hydrochloride (40.0 g, 155 mmol) in dry MeOH (130 mL, N2 degassed) was added to a nitrogen purged 250 mL stainless steel pressure vessel. Subsequently, the aged catalyst solution from above was added into the vessel under nitrogen flow. The resulting mixture was degassed three times with H2 and then (2.0 MPa, ca. 300 psi) heated at 50 °C under 2.0 MPa (ca. 300 psi) of H2 for 3 days with stirring. After the reaction was deemed complete by HPLC analysis, the reaction vessel allowed to cool to room temperature and was purged with nitrogen. The reaction mixture was concentrated in vacuo to yield a dark brown oil. This concentrate was taken up in EtOAc and saturated aqueous NaHC03 was added. The mixture was stirred at room temperature for half hour and the organic phase was separated. The aqueous phase was extracted with three times with EtOAc. The combined organic phases were washed with brine, dried over Na2S04, and concentrated under vacuum. The residue was purified by column chromatography over silica gel to (eluent: 50% EtOAc in hexane) afford the title compound as a yellow oil (27.4 g, 73%). *H NM (400 MHz, CDCI3) 67.33-7.27 (m, 4H), 7.27-7.23 (m, IH), 4.83 (d, J = 48.8 Hz, IH), 3.77-3.72 (m, IH), 3.64-3.52 (m, 3H), 3.24-3.18 (m, IH), 2.97-2.92 (m, IH), 2.16-2.04 (m, 2H), 1.77-1.65 (m, 3H).
Step 5. ((3S,4/?)-3-fluoropiperidin-4-yl)methanol hydrochloride
Figure imgf000150_0001
HCI 5] To a stirred solution of ((3S,4 ?)-l-benzyl-3-fluoropiperdin-4-yl)methanol (24.0 g, 108 mmol) in MeOH (100 mL) was added 10% Pd/C (2.4 g,) and 6M aqueous HCI (18 mL). The mixture was purged with hydrogen three times, and hydrogenated at atmospheric pressure. After stirring at room temperature for 6 hours, the starting material was consumed. The reaction vessel was purged with nitrogen. The reaction mixture then was filtered through celite, the filter pad rinsed with MeOH, and the filtrate concentrated in vacuo. The residue obtained was dissolved in a solution of methanol/isopropylacetate (v/v = 1/1), and the mixture was filtered. The filtrate was concentrated and then dissolved in 10% methanol/isopropylacetate. The title compound crystallized from the solution as an off-white solid. The solid was isolated by filtration, washed twice with 10% methanol/isopropylacetate and dried under vacuum to afford the title compound as an off-white solid (11.2 g, 62%). *H NM (400 MHz, CD3OD) δ 5.10 (d, J = 46.0 Hz, IH), 3.69-3.58 (m, 2H), 3.52 (dd, J=10.8 and 6.4 Hz, IH), 3.44-3.37 (m, IH), 3.28 (dd, J=40 and 14 Hz, IH), 3.13-3.06 (m, IH), 2.08-1.89 (m, IH), 1.88-1.82 (m, IH), 1.77-1.63 (m, IH).
Step 6. (3S,4/?)-4-methylbenzyl 3-fluoro-4-(hydroxymethyl)piperidine-l-carboxylate
Figure imgf000151_0001
[0176] To a stirred solution of 4-methylbenzyl alcohol (36.0 g, 296 mmol) in dimethylformamide (300 mL) was added N,N'-carbonyldiimidazole (48.0 g, 296 mmol). The mixture was stirred at room temperature for one hour and the solid ((3S,4/?)-3-fluoropiperidin-4-yl)methanol hydrochloride (50 g, 296 mmol) was added portionwise. This reaction mixture was stirred at 50°C overnight and allowed to cool to room temperature. The solvent was removed under reduced pressure and the residue was dissolved in ethylacetate. The solution was washed with 0.5M aqueous HCI, saturated NaHC03, brine, dried over Na2S04 and concentrated under reduce pressure. The residue was purified by column chromatography over silica gel (50% ethylacetate-hexane) to afford the title compound as a colorless oil, which gradually became a white solid on standing (65.0 g, 78%). 1H NMR (400 MHz, CDCI3) δ 7.25 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.09 (s, 2H), 4.83-4.46 (m, 2H), 4.37-4.22 (m, IH), 3.46-3.40 (m, IH), 3.32-3.27 (m, IH), 3.00-2.72 (m, 2H), 2.35 (s, 3H), 1.86- 1.70 (m, IH), 1.67-1.54 (m, 2H).
Step 7. (3S,4/?)-4-methylbenzyl 3-fluoro-4-((methylsulfonyloxy)methyl)piperidine-l-carboxylate
Figure imgf000151_0002
[0177] To a stirred solution of ((3S,4/?)-4-methylbenzyl 3-fluoro-4-(hydroxymethyl)-piperidine-l- carboxylate (55.0 g, 196 mmol) and diisopropylethylamine (80 mL, 455 mmol) in dichloromethane (500 mL) was added neat methanesulfonylchloride (25.2 mL, 325 mmol) dropwise at ice-water bath temperature under N2. The mixture was allowed to warm to room temperature and was stirred for 30 min. The mixture was diluted with dichloromethane and water was added. The aqueous layer was extracted with dichloromethane and the combined organic layers were dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (30% ethylacetate:hexane) to afford the title compound as a white powder (59.0 g, 84%). 1H NM (400 M Hz, CDCI3) δ 7.25 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.10 (s, 2H), 4.94-4.26 (m, 3H), 4.25- 4.13 (m, 2H), 3.03 (s, 3H), 3.02-2.72 (m, 2H), 2.35 (s, 3H), 2.19-2.03 (m, 1H), 1.69-1.53 (m, 2H).
Step 8. (3S,4/?)-4-methylbenzyl 4-(azidomethyl)-3-fluoropiperidine-l-carboxylate
Figure imgf000152_0001
[0178] To a stirred solution of (3S,4/?)-4-methylbenzyl 3-fluoro-4-((methylsulfonyloxy)methyl) piperidine-1- carboxylate (59.0 g, 164 mmol) in dimethylformamide (200 m L) was added sodium azide (21.3 g, 328 mmol) at room temperature. The mixture was heated at 90 °C overnight and then allowed to cool to room temperature. The reaction mixture was diluted with ethylacetate, followed by addition of water. The aqueous layer was separated and extracted with ethylacetate. The combined organic layers were dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (20% ethylacetate:hexane) to afford the title product as a colorless oil (50.2 g, 92%).^ N M R (400 M Hz, CDCI3) δ 7.25 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.10 (s, 2H), 4.84-4.16 (m, 3H), 3.45-3.40 (m, 1H), 3.32-3.27 (m, 1H), 3.00-2.70 (m, 2H), 2.35 (s, 3H), 1.86-1.71 (m, 1H), 1.68-1.57 (m, 2H).
Step 9. (3S,4/?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride
Figure imgf000152_0002
HCI
[0179] To a stirred solution of (3S,4/?)-4-methylbenzyl 4-(azidomethyl)-3-fluoropiperidine-l-carboxylate (50.0 g, 164 mmol) in MeOH (500 m L) was added SnCI2 H20 (83.8 g, 328 mmol). The mixture was stirred at room temperature overnight. The solvent was removed under reduced pressure and the residue was diluted with ethylacetate. The organic layer was washed with 10% NaOH, water, and brine. The organic phase was dried over Na2S04 and concentrated to afford the crude (3S,4 ?)-4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate free base product as a yellow oil. This material was dissolved in toluene/MeOH (95/5, v/v) and HCI/Et20 (82 mL, 2.0M, 164 mmol) solution was added at room temperature. The mixture was stirred at r.t. and the product crystallized from the solution as a white solid. The solid was collected by filtration, extracted twice with chilled toluene and dried under vacuum to afford the title compound as a white solid (33.0 g, 66%). 1H NMR (400 MHz, CD3OD) δ 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.86-4.67 (m, 1H), 4.51-4.45 (m, 1H), 4.27-4.23 (m, 1H), 3.21-2.87 (m, 4H), 2.35 (s, 3H), 2.19-1.97 (m, 1H), 1.70-1.53 (m, 2H). [ct]D = -31° (c = 1.0, EtOH, 22 °C)
EXAMPLE l.B. (3/?,4S)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride.
Figure imgf000153_0001
HCI
[0180] The title compound was prepared in analgous fashion to (3S,4/?)-4-methylbenzyl 4- (aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (Example l.A) using the enantiomeric (S)-(-)-l-[(S)-2-(2'-(diphenylphosphino)phenyl]ferrocenylethyldicyclohexylphosphine (CA number 849925-19-5, available from Solvias as Walphos # SL-W003-2) as the chiral ligand in Step 4.
EXAMPLE l.C. (3S,4 ?)-tert-butyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate.
Figure imgf000153_0002
Step 1: (3S, 4 ?)-tert-butyl 3-fluoro-4-(hydroxymethyl)piperidine-l-carboxylate
Figure imgf000154_0001
[0181] To ((3S, 4 ?)-3-fluoropiperidin-4-yl)methanol hydrochloride (1.0 g, 5.9 mmol) in DCM (20 mL) was added triethylamine (1.23 mL, 8.88 mmol) and (Boc)20 (1.63 mL, 7.1 mmol) at 0 °C with stirring. The mixture was stirred at room temperature overnight, diluted with DCM, followed by addition of sat. NaHC03. The organic layer was separated, washed twice with water, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (60% hexanes in EtOAc) to afford title compound as a white powder (784 mg, 49%). H NM (400 MHz, CDCI3) δ 4.82 (d, J = 48.0 Hz, 1H), 4.50-4.15 (m, 2H), 3.75-3.59 (m, 2H), 2.92-2.71 (m, 2H), 1.87-1.70 (m, 1H), 1.58-1.48 (m, 2H), 1.46 (s, 9H).
Step 2: (3S,4 ?)-tert-butyl 3-fluoro-4-((methylsulfonyloxy)methyl)-piperidine-l-carboxylate
Figure imgf000154_0002
[0182] To a stirred solution of ((3S, 4 ?)-tert-butyl 3-fluoro-4-(hydroxymethyl)piperidine-l-carboxylate (784 mg, 2.91 mmol) in DCM (10 mL) was added MsCI (0.24 mL, 4.84 mmol) and diisopropylethylamine (0.75 mL, 6.76 mmol) dropwise at 0 °C. The mixture was stirred at room temperature for 30 min, diluted with DCM and water. The organic layer was separated and the aqueous layer was extracted with DCM. The combined organic layers were dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (60% EtOAc in hexanes) to afford the title compound as a white powder (844 mg, 93%). H NMR (400 MHz, CDCI3) δ 4.77 (d, J = 48.0 Hz, 1H), 4.55-4.14 (m, 4H), 3.04 (s, 3H), 2.98-2.71 (m, 2H), 2.17-2.01 (m, 1H), 1.65-1.50 (m, 2H), 1.46 (s, 9H).
Step 3: (3S, 4 ?)-tert-butyl 4-(azidomethyl)-3-fluoropiperidine-l-carboxylate
Figure imgf000154_0003
[0183] To a stirred solution of (3S, 4 ?)-tert-butyl 3-fluoro-4-((methylsulfonyloxy)-methyl)piperidine-l- carboxylate (844 mg, 2.71 mmol) in DM F (10 mL) was added NaN3 (352 mg, 5.42 mmol) at room temperature. The mixture was heated to 90 °C overnight, allowed to cool to room temperature. Water and EtOAc were added, the organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic layers were dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (20% EtOAc in hexanes) to afford the title compound as a colorless oil (697 mg, 100%). *H N M (400 M Hz, CDCI3) δ 4.71 (d, J = 48 Hz, 1H), 4.51-4.12 (m, 2H), 3.45-3.40 (m, 1H), 3.31-3.27 (m, 1H), 2.93-2.68 (m, 2H), 1.86-1.69 (m, 1H), 1.64- 1.58 (m, 1H), 1.55-1.54 (m, 1H), 1.46 (s, 9H).
Step 4: (3S,4 ?)-tert-butyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate
Figure imgf000155_0001
[0184] To a stirred solution of ((3S, 4 ?)-tert-butyl 4-(azidomethyl)-3-fluoropiperidine-l-carboxylate (697 mg, 2.7 mmol) in MeOH (10 m L) was added SnCI2 'H20 (1.2 g, 5.4 mmol) and the mixture was stirred at room temperature overnight. The solvent was removed under reduced pressure and the residue was diluted with EtOAc. The organic layer was washed with 10% NaOH (aq), water, brine, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (50% EtOAc in hexanes) to afford title compound as a white powder (256 mg, 41%). 1H N M R (400 M Hz, CDCI3) δ 4.77 (d, J = 48.0 Hz, 1H), 4.49-4.15 (m, 2H), 2.94-2.68 (m, 4H), 1.66-1.59 (m, 1H), 1.54- 1.49 (m, 2H), 1.46 (s, 9H).
EXAM PLE l. D. N-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine
dihydrochloride.
Figure imgf000155_0002
2HCI Step 1: (3S,4 ?)-tert-butyl 4-(([l,2,4]triazolo[4 -a]pyrazin-5-ylamino)methyl)-3-fluoropiperidine- 1-carboxylate
Figure imgf000156_0001
[0185] A mixture of 5-bromo-[l,2,4]triazolo[4,3-a]pyrazine (102 mg, 0.51 mmol), (3S,4R)-tert-butyl 4- (aminomethyl)-3-fluoropiperidine-l-carboxylate (80 mg , 0.34 mmol) and DIPEA (1.2 mL, 1.0 mmol) in ethylene glycol (2 mL) was heated to 110 °C in the sealed tube for 7 hr under N2 atmosphere. The mixture was allowed to cool to rt and concentrated. The concentrate was partitioned into DCM and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (MeOH/DCM=50/l) to afford the title compound as an off-white powder (60 mg, 50%). MS (ESI) calcd for C16H23FN602: 350.2; found: 351.3[M+H]. 1H NMR (400 MHz, CDCI3) δ 8.72 (s, 1H), 7.41 (d, J = 4.8 Hz, 1H), 7.34 (d, J = 4.8 Hz, 1H), 6.55-6.47 (m, 1H), 4.90-4.65 (m, 1H), 4.62-4.35 (m, 1H), 4.33-4.05 (m , 1H), 3.74-3.64 (m, 2H), 2.96-2.62 (m, 2H), 2.24 -2.04 (m, 1H), 1.73-1.58 (m, 1H), 1.46 (s, 9H).
Step 2: N-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine
dihydrochloride
Figure imgf000156_0002
[0186] To a solution of 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoropiperidine-l- carboxylate (410 mg, 1.17 mmol) in DCM/MeOH (5 mL/ 5 mL) was added HCI solution in ether (21 mL, 1.0 M) at room temperature. After stirring overnight the mixture was concentrated to afford the title compound as an off-white powder (480 mg, 100%). Η NMR (400 M Hz, dg-DMSO) δ 9.40 (s, 1H), 7.96 (d, J = 5.6 Hz 1H), 7.26 (d, J = 5.6 Hz, 1H), 3.82-3.70 (m, 1H), 3.62-3.48 (m, 2H), 3.29-3.19 (m, 1H), 3.14-3.06 (m, 1H), 2.95-2.83 (m, 1H), 2.42-2.24 (m, 1H), 1.93-1.85 (m, 1H), 1.71-1.60 (m, 1H). EXAMPLE I.E. N-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4 -a]pyrazin-5-amine dihydrochloride.
Figure imgf000157_0001
2HCI
Step 1. (3S, 4 ?)-tert-butyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000157_0002
[0187] A mixture of 8-chloro-[l,2,4]triazolo[4,3-a]pyrazine (2.00 g, 12.94 mmol), (3S, 4 ?)-tert-butyl 4- (aminomethyl)-3-fluoropiperidine-l-carboxylate (2.86 g , 12.32 mmol) and DIPEA (4.07 mL, 24.64 mmol) in n-butyl alcohol (40 mL) was heated to 120 °C in the sealed tube under N2 atmosphere. After stirring overnight, the mixture was cooled to rt and concentrated under reduce pressure. The concentrate was partitioned into DCM and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (MeOH/DCM = 1/20) to afford the title compound as a pale-yellow powder (2.91g, 67%). MS (ESI) calcd for C16H23FN602: 350.2; found: 351.7[M+H]. *H NM (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.70 (d, J = 4.8 Hz, 1H), 7.31 (d, J = 4.8 Hz, 1H), 4.86-4.73 (m, 1H), 4.42-4.35 (m, 1H), 4.19-4.16 (m, 1H), 3.67-3.62 (m , 1H), 3.59-3.54 (m, 1H), 3.05-2.74 (m, 2H), 2.25 -2.10 (m, 1H), 1.67-1.53 (m, 2H), 1.46 (s, 9H).
Step 2. N-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-8-amine
dihydrochloride
Figure imgf000158_0001
2HCI
[0188] To a solution of (3S,4 ?)-tert-butyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (1.50 g, 4.29 mmol) in MeOH (21 mL) was added HCI in ether (21 mL, 1.0 M, 21.0 mmol) at room temperature. After stirring overnight, the mixture was concentrated to afford the title compound as a pale-yellow powder (1.38 g, 99%). MS (ESI) calcd for CnHi5FN6: 250.1; found: 251.8[M+H]. *H NM (400 MHz, dg-DMSO) δ 10.65 (brs, 1H), 9.70 (brs, 1H), 9.43 (s, 1H), 8.80 (brs, 1H), 7.98 (d, J = 5.2 Hz, 1H), 7.25 (d, J = 5.2 Hz, 1H), 6.40 (brs, 2H), 5.17 (d, J = 46.4 Hz, 1H), 3.85- 3.79 (m, 1H), 3.62-3.51 (m, 2H), 3.27-3.04 (m, 2H), 2.92-2.83 (m, 1H), 2.40-2.26 (m, 1H), 1.95-1.91 (m, 1H), 1.72-1.59 (m, 1H).
[0189] The compounds of the foregoing Examples can be used in the following procedures.
EXAMPLE 1.1. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyrazin-2-ylamino)methyl)
piperidine-l-carboxylate (El-26.2).
Figure imgf000158_0002
Step 1. [l,2,4]triazolo[l,5-a]pyrazin-2-amine
Figure imgf000158_0003
[0190] To a stirred solution of pyrazin-2-amine (25.0 g, 0.26 mol) in dioxane (300 mL) was added O- ethyl carbonisothiocyanatidate (37.90 g, 0.29 mol) dropwise under ice-water bath. After stirring for 18 hrs at rt, the mixture was concentrated. A mixture of TEA (109 mL, 0.78 mol) and hydroxylamine hydrochloride (72.50 g, 1.04 mol) in MeOH/EtOH (200 mL : 200 mL) was then added to the suspension The resulting mixture was stirred for 1 hr at rt, then the heated to reflux to afford a clear solution. After refluxing for additional 4 hs, the mixture was cooled to rt and concentrated to afford the crude which was recrystallized with 95% ethanol to afford the title compound as a pale yellow solid (32.03 g, 91%). MS (ESI) calcd for C5H5N5: 135.1; found: 136.3 [M+H]. *H NM (400 MHz, d6- DMSO) δ 8.83 (d, J = 1.2 Hz, 1H), 8.68 (dd, J = 4.4 and 1.2 Hz, 1H), 7.97 (d, J = 4.4 Hz, 1H), 6.45 (brs, 2H).
Step 2: 2-bromo-[l,2,4]triazolo[l,5-a]pyrazine
Figure imgf000159_0001
[0191] To a stirred solution of [l,2,4]triazolo[l,5-a]pyrazin-2-amine (10.00 g, 74.0 mmol) in acetonitrile (350 mL) were added isopentyl nitrite (20 mL, 147 mmol) and CuBr (21.00 g, 147.98 mmol). The mixture was heated to reflux for 2 hrs. The reaction solution was cooled to rt and concentrated. The residue was treated with ammonia hydrate and extracted with DCM. The organic phase was dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography over silica gel (hexane/acetone = 15/1) to afford the title compound as an off-white powder (1.39 g, 9%). MS (ESI) calcd for C5H3BrN4: 198.0; found: 199.2. 201.2 [M+H]. *H NM R (400 MHz, CDCI3) δ 9.25 (d, J = 1.2 Hz, 1H), 8.51 (dd, J = 4.4, 1.2 Hz, 1H), 8.25 (d, J = 4.4 Hz, 1H).
Step 3. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyrazin-2-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate
Figure imgf000159_0002
[0192] To a stirred suspension of (3S,4/?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate dihydrochloride (870 mg, 2.75 mmol) in f-butyl alcohol (20 mL) was added 2-bromo- [l,2,4]triazolo[l,5-a]pyrazine (500 mg, 2.54 mmol), Brettphos precatalyst (50 mg), Brettphos (50 mg) and Cs2C03 (2.45 g, 7.52 mmol). The mixture was heated to 100 °C under nitrogen with stirring overnight. The reaction mixture was allowed to cool to room temperature, diluted with DCM, and filtered through the celite. The filtrate was washed with water, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (50% hexanes in EtOAc) to afford title compound as an off-white powder (255 mg, 26%). MS (ESI) calcd for C2oH23FN602: 398.2; found: 399.4 [M+H]. *H NM (400 MHz, CD3OD) δ 8.78 (d, J = 1.2 Hz, 1H), 8.54 (dd, J = 4.8 and 1.2 Hz, 1H), 8.00 (d, J = 4.8 Hz, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.10-5.04 (m, 2H), 4.87-4.72 (m, 1H), 4.49-4.40 (m, 1H), 4.28-4.20 (m, 1H), 3.49-3.43 (m, 1H), 3.38-3.33 (m, 1H), 3.14- 2.78 (m, 2H), 2.33 (s, 3H), 2.20-2.02 ( m, 1H ), 1.69-1.50 (m, 2H).
EXAMPLE 1.1a. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]-pyrazin-2-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-26.2a).
Figure imgf000160_0001
[0193] To a solution of (3S, 4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyrazin-2-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (251 mg, 0.63 mmol) in DCM (5 mL) was added 0.5 M methylsulfonic acid in MeOH (1.26 mL, 0.63 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as an off-white powder (297 mg, 97%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.4 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.11 (d, J = 1.2 Hz, 1H), 8.98 (dd, J = 4.8, 1.2 Hz, 1H), 8.30 (d, J = 4.8 Hz, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.10-5.04 (m, 2H), 4.87-4.71 (m, 1H), 4.50-4.41 (m, 1H), 4.28-4.21 (m, 1H), 3.57- 3.52 (m, 1H), 3.47-3.42 (m, 1H), 3.14-2.79 (m, 2H), 2.71 (s, 3H), 2.33 (s, 3H), 2.22-2.04 ( m, 1H ), 1.70- 1.52 (m, 2H).
EXAMPLE 1.2. (3S,4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-1.6).
Figure imgf000160_0002
[0194] To a stirred solution of (4-(difluoromethyl)phenyl)methanol (120 mg, 0.42 mmol) in DMSO (6 mL) was added CDI (81 mg, 0.50 mmol) at room temperature. After stirred for lh, the N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride salt (350 mg, 1.05 mmol) was added. The mixture was heated to 50°C in a sealed tube under N2 atmosphere. After stirring overnight, the mixture was cooled to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 50/1) to afford the title compound as a yellow powder (60 mg, 43%). MS (ESI) calcd for C2oH2iF3N602: 434.2; found: 435.5 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.70 (d, J = 4.8 Hz, 1H), 7.54 (d, J = 7.6 Hz, 2H), 7.48 (d, J = 7.6 Hz, 2H), 7.30 (d, J = 4.8 Hz, 1H), 6.76 (t, J = 56.0 Hz, 1H), 5.20 (s, 2H), 4.86-4.77 (m, 1H), 4.56-4.45 (m, 1H), 4.34-4.24 (m, 1H), 3.70 -3.57 (m, 2H), 3.11-2.87 (m, 2H), 2.34-2.15 (m, 1H), 1.75- 1.60 (m, 2H).
EXAMPLE 1.2a. (3S,4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-1.6a).
Figure imgf000161_0001
[0195] To a stirred solution of (3S,4R)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (256 mg, 0.54 mmol) in MeOH (3 mL) was added the 0.5M methanesulfonic acid in methanol (1.08 mL, 0.54 mmol). After stirring for 30 min at room temperature, the solution was concentrated to afford the title compound as an off-white powder (290 mg, 93%). MS (ESI) calcd for C20H21F3N6O2: 434.2; found: 435.5 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.96 (d, J = 5.6 Hz, 1H), 7.54 (d, J = 7.6 Hz, 2H), 7.48 (d, J = 7.6 Hz, 2H), 7.23 (d, J = 5.6, 1H), 6.68 (t, J = 56.0 Hz, 1H), 5.20 (s, 2H), 4.86-4.77 (m, 1H), 4.57-4.45 (m, 1H), 4.35-4.25 (m, 1H), 3.82-3.78 (m, 1H), 3.66-3.57 (m, 1H), 3.24-2.90 (m, 2H), 2.70 (s, 3H), 2.38-2.20 (m, 1H), 1.81- 1.60 (m, 2H).
EXAMPLE 1.3. (3S,4 ?)-4-methylbenzyl 3-fluoro-4-((3-methyl-[l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)- methyl)piperidine-l-carboxylate (El-1.26).
Figure imgf000162_0001
Step 1: 2-chloro-3-hydrazinylpyrazi
Figure imgf000162_0002
[0196] To a stirred solution of 2,3-dichloropyrazine (10.0 g, 67.6 mmol) in ethanol (95%, 120 ml) was added 85% hydrazine hydrate (25.6 mL, 338 mmol) dropwise at room temperature. The mixture was stirred for 4 hours and cooled to ice-water bath temperature. The resulting precipitate was isolated by filtration and washed with cold ethanol (95%) to give the title compound as a light yellow powder (6.5 g, 67%) which was used in the next step without further purification.
Step 2: 8-chloro-3-methyl-[l,2,4]triazolo[4,3-a]pyrazine
Figure imgf000162_0003
[0197] To a stirred solution of 2-chloro-3-hydrazinylpyrazine (2.0 g, 14 mmol) in xylene (20 mL) was added triethyl orthoformate (5.8 mL, 32 mmol). The mixture was heated under reflux overnight and then cooled to room temperature. The resulting precipitate was collected by filtration to afford the title compound as a brown powder (2.0 g, 87%). MS (ESI) calcd forC6H5CIN4: 168.0 ; found: 169.2 [M+H]. *H NM (400 MHz, CDCI3) δ 7.80 (d, J = 4.8 Hz, 1H), 7.71 (d, J = 4.8 Hz, 1H), 2.83 (s, 3H).
Step 3: (3S,4R)-4-methylbenzyl 3-fluoro-4-((3-methyl-[l,2,4]triazolo[4,3-a]-pyrazin-8-ylamino)- methyl)piperidine-l-carboxylate
Figure imgf000163_0001
[0198] A mixture of (3S,4 )-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (100 mg, 0.35 mmol), 8-chloro-3-methyl-[l,2,4]triazolo[4,3-a]pyrazine (66 mg, 0.39 mmol) and DIPEA (0.12 mL, 0.70 mmol) in butyl alcohol (3 mL) was heated to 120 °C. After stirring overnight at 120 °C, the orange solution was concentrated. The concentrate was purified by column chromatography over silica gel (hexane/ ethyl acetate = 1:3) to afford the title compound as a white powder (87 mg, 67%). MS (ESI) calcd for C21H25FN602: 412.2 ; found: 413.0 [M+H]. *H NMR (400 MHz, CD3OD) δ 7.70 (d, J = 5.2 Hz, 1H), 7.26 (d, J = 5.2 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.88-4.74 (m, 1H), 4.52-4.43 (m, 1H), 4.29-4.24 (m, 1H), 3.76-3.59 (m, 2H), 3.05- 2.88 (m, 2H), 2.74 (s, 3H), 2.33 (s, 3H), 2.29-2.17 (m, 1H), 1.73-1.58 (m, 2H).
EXAMPLE 1.3a. (3S,4 ?)-4-methylbenzyl 3-fluoro-4-((3-methyl-[l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)- methyl)piperidine-l-carboxylate methanesulfonate (El-1.26a).
Figure imgf000163_0002
[0199] To a stirred solution of (3S,4R)-4-methylbenzyl 3-fluoro-4-((3-methyl-[l,2,4]triazolo[4,3-a]- pyrazin-8-ylamino)methyl)piperidine-l-carboxylate (80 mg, 0.20 mmol) in DCM/MeOH (2 mL/1 mL) was added methanesulfonic acid in methanol (0.20 mL, 1.0 M, 0.20 mmol). The mixture was stirred for 15min, and concentrated to afford the title compound as a white powder (91 mg, 100%). MS (ESI) calcd for C21H25FN602: 412.2 ; found: 413.0 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 7.84 (d, J = 5.2 Hz, 1H), 7.31 (d, J = 5.2 Hz, 1H), 7.24 (d, J =7.6 Hz, 2H), 7.17 (d, J =7.6 Hz, 2H), 5.02 (s, 2H), 4.95- 4.77 (m, 2H), 4.36-4.20 (m, 1H), 4.15-4.00 (m, 1H), 3.68-3.38 (m, 2H), 3.17-2.79 (m, 2H), 2.70 (s, 3H), 2.34 (s, 3H), 2.29 (s, 3H), 2.25-2.14 (m, 1H), 1.70-1.60 (m, 1H), 1.48-1.37 (m, 1H). EXAMPLE 1.4. (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-1.3).
Figure imgf000164_0001
[0200] To a solution of (4-chlorophenyl)methanol (109 mg, 0.77 mmol) in dried DMSO (4 mL) was added CDI (136 mg, 0.84 mmol) at room temperature. After stirring for 1.5 h, N-(((3S,4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-8-amine dihydrochloride salt (200 mg, 0.70 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere. After stirring overnight, the mixture was diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 10/1) to afford the title compound as a white powder (95 mg, 38%). MS (ESI) calcd for C19H20CIFN6O2: 418.1; found: 419.2 [M+H]. *H NM (400 MHz, d6-DMSO) δ 9.21 (s, 1H), 8.34-8.28 (m, 1H), 7.76 (d, J = 4.8 Hz, 1H), 7.44 (d, J = 8.0 Hz, 2H), 7.38 (d, J = 8.0 Hz, 2H), 7.28 (d, J = 4.8 Hz, 1H), 5.10-5.03 (m, 2H), 4.90-4.74 (m, 1H), 4.30-4.24 (m, 1H), 4.09-4.06 (m, 1H), 3.56-3.51 (m, 1H), 3.46-3.38 (m, 1H), 3.15-2.68 (m, 2H), 2.25-2.14 (m, 1H), 1.59-1.56 (m, 1H), 1.47-1.36 (m, 1H).
EXAMPLE 1.4a. (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-1.3a).
Figure imgf000164_0002
CH3SO3H
[0201] To a solution of (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (95 mg, 0.23 mmol) in DCM/MeOH (lml/lml) was added methanesulfonic acid (0.23 mL,1.0 M, 0.23 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a white powder (116 mg, 100%). MS (ESI) calcd for C19H20CIFN6O2: 418.1; found: 419. 2 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 10.20 (brs, 1H), 9.36 (s, 1H), 7.93 (d, J = 5.6 Hz, 1H), 7.44 (d, J = 8.0 Hz, 2H), 7.38 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 5.6 Hz, 1H), 5.11-5.04 (m, 2H), 4.94-4.78 (m, 1H), 4.34-4.26 (m, 1H), 4.11-4.08 (m, 1H), 3.64-3.59 (m, 1H), 3.49- 3.41 (m, 1H), 3.13-2.67 (m, 2H), 2.34 (s, 3H), 2.30-2.13 (m, 1H), 1.69-1.64 (m, 1H), 1.48-1.38 (m, 1H).
EXAMPLE 1.5. (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-1.4).
Figure imgf000165_0001
[0202] A solution of (4-fluorophenyl)methanol (144 mg, 1.14 mmol) and CDI (205 mg, 1.39 mmol) in DMSO (5.0 mL) was stirred at room temperature for 1 h. After the alcohol was consumed, N- (((3S,4R)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride (300 mg, 0.92 mmol) was added. The resulting mixture was heated to 50 °C under N2 atmosphere overnight. The mixture was diluted with EtOAc, washed with water, then brine, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (100% EtOAc) to afford the title compound as a white powder (100 mg, 27%). MS (ESI) calcd for C19H20F2N6O2: 402.2; found: 403.2 [M+H]. *H NM R (400 MHz, dg-DMSO) δ 8.20 (s, 1H), 8.29 (t, J = 5.6 Hz, 1H), 7.75 (d, J = 4.4 Hz, 1H), 7.45-7.35 (m, 2H), 7.27 (d, J = 4.4 Hz, 1H), 7.20 (t, J = 8.0 Hz, 2H), 5.05 (s, 2H), 4.91-4.72 (m, 1H), 4.32-4.21 (m, 1H), 4.12-4.04 (m, 1H), 3.57-3.51 (m, 1H), 3.43-3.37 (m, 1H), 3.14-2.72 (m, 2H), 2.27-2.10 (m, 1H), 1.61-1.53 (m, 1H), 1.47-1.34 (m, 1H).
EXAMPLE 1.5a. (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methylsulfonate (El-1.4a).
Figure imgf000165_0002
CH3SO3H [0203] To a stirred solution of (3S,4 )-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)- methyl)-3-fluoropiperidine-l-carboxylate (100 mg, 0.25 mmol) in DCM/MeOH (2 mL, 1:1) was added methylsulfonic acid in methanol (0.25 mL, 1.0 M, 0.25 mmol) at room temperature. After stirring for 30 min, the solution was concentrated in vacuo to afford the title compound as an off-white powder (124 mg, 100%). MS (ESI) calcd for C19H20F2N6O2: 402.2; found: 403.2[M+H]. *H NMR (400 MHz, d6- DMSO) δ 9.33 (s, 1H), 7.97 (d, J = 5.6 Hz, 1H), 7.44-7.34 (m, 2H), 7.25 (d, J = 5.6 Hz, 1H), 7.13-7.03 (m, 2H), 5.11 (s, 2H), 4.88-4.75 (m, 1H), 4.54-4.43 (m, 1H), 4.32-4.22 (m, 1H), 3.80-3.75 (m, 1H), 3.63- 3.58 (m, 1H), 3.20-2.84 (m, 2H), 2.71 (s, 3H), 2.37-2.14 (m, 1H), 1.81-1.58 (m, 2H).
EXAMPLE 1.6. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-3-ylamino)-methyl)-3- fluoro- piperidine-l-carboxylate (El-7.2).
Figure imgf000166_0001
Step 1: 2-hydrazinylpyrazine
Figure imgf000166_0002
[0204] 2-Chloropyrazine (2.0 g, 17.5 mmol) was added dropwise to a 35% aqueous solution of hydrazine hydrate (25.8 g, 97.8 mmol) at 63-65 °C, the addition rate was carefully monitored to ensure that the reaction temperature did not exceed 65 °C. Following the addition, the mixture was heated to 65 °C. After stirring overnight, the reaction was cooled to room temperature. The solvent was evaporated to afford the title compound as a yellow powder (1.5 g, 75%). MS (ESI) calcd for C4H6N4: 110.1; found: 111.4 [M+H]. *H NMR (400 MHz, CD3OD) δ 8.10 (d, J = 1.6 Hz, 1H), 8.00 (dd, J = 3.2, 1.6 Hz, 1H), 7.73(d, J = 3.2 Hz, 1H).
Step 2. (3S,4R)-4-methylbenzyl 3-fluoro-4-((2-(pyrazin-2-yl)-hydrazinecarboxamido)methyl)- piperidine-l-carboxylate
Figure imgf000167_0001
[0205] A solution of (3S, 4 ?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate (600 mg, 2.59 mmol) in dichloromethane (3 mL) was added to a solution of triphosgene (260 mg, 2.57 mmol) in dichloromethane (5 m L) at 0 °C under nitrogen. Triethylamine (0.68 mL, 4.96 mmol) in dichloromethane (3 m L) was then added dropwise and the mixture was stirred at room temperature. After stirring for 2 hours, the mixture was cooled to 0 °C and 2-hydrazinyl pyrazine (272 mg, 2.46 mmol) in dichloromethane (5 m L) was added. The reaction mixture was stirred overnight at room temperature. The mixture was diluted with dichloromethane, and washed with saturated NaHC03, brine, dried over Na2S04 and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (5% MeOH-DCM) to afford the title compound as a yellow powder (423 mg, 40 %). MS (ESI) calcd for C20H25FN6O3: 416.2; found: 417.2 [M+H]. *H NM (400 M Hz, CD3OD) δ 8.09 (d, J = 2.0 Hz, 2H), 7.94 (d, J = 2.0 Hz, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.09-5.03 (m, 2H), 4.77-4.56 (m, 1H), 4.45-4.35 (m, 1H), 4.24-4.16 (m, 1H), 3.26-3.21 (m, 1H), 3.19-3.12 (m, 1H), 3.07-2.76 (m, 2H), 2.33 (s, 3H), 1.98-1.82 ( m, 1H ), 1.57-1.39 (m, 2H).
Step 3. (3S, 4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-3-ylamino)-methyl)-3-fluoro- piperidine-l-carboxylate
Figure imgf000167_0002
[0206] Hexachloroethane (934 mg, 4.0 mmol) was added portionwise to a stirred solution of triphenylphosphine (1.05 g, 4.0 mmol) and triethylamine (1.13 ml, 8.0 mmol) in dry THF (10 mL) at room temperature. After stirring overnight, the resulting suspension was filtered through celite, and the filtrate was concentrated in vacuo. The residue was dissolved in ethylacetate, and the solution was washed with water, brine, dried over Na2S04 and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (5% MeOH-DCM) to afford the title compound as a yellow powder (113 mg, 28%). MS (ESI) calcd for C2oH23FN602: 398.2; found: 399.3 [M+H]. *H NM (400 MHz, CD3OD) δ 8.98 (d, J = 1.6 Hz, 1H), 7.98 (dd, J = 5.2, 1.6 Hz, 1H), 7.66 (d, J = 5.2 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.94-4.77 (m, 1H), 4.49-4.43 (m, 1H), 4.29-4.21 (m, 1H), 3.61-3.56 (m, 1H), 3.52-3.46 (m, 1H), 3.13-2.81 (m, 2H), 2.33 (s, 3H), 2.28- 2.13 ( m, 1H ), 1.73-1.52 (m, 2H).
EXAMPLE 1.7. (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-2.3).
Figure imgf000168_0001
[0207] To a solution of (4-chlorophenyl)methanol (65 mg, 0.45 mmol) in DMSO (2.5 mL) was added CDI (68 mg, 0.42 mmol) at room temperature. After stirring for 1 hr, N-(((3S,4R)-3-fluoropiperidin-4- yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine dihydrochloride salt (100 mg, 0.35 mmol) was added. The mixture was heated to 50 °C in a sealed tube under N2 atmosphere with stirring overnight. The mixture was cooled to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 50:1) to afford the title compound as a yellow powder (75 mg, 55%). MS (ESI) calcd for C19H20CIFN6O2:418.1; found: 419.2 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 9.20 (s, 1H), 8.29 (t, J = 4.8 Hz, 1H), 7.75 (d, J = 4.8 Hz, 1H), 7.43 (d, J = 8.0 Hz, 2H), 7.38 (d, J = 8.0 Hz, 2H), 7.27 (d, J = 4.8 Hz, 1H), 5.06 (s, 2H), 4.92 -4.72 (m, 1H), 4.32-4.20 (m, 1H), 4.11-4.02 (m, 1H), 3.58-3.39 (m, 2H), 3.22-2.56 (m, 3H), 2.28-2.10 (m, 1H), 1.62-1.52 (m, 1H), 1.47-1.34 (m, 1H).
EXAMPLE 1.7a. (3S,4 ?)-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-2.3a).
Figure imgf000169_0001
[0208] To a stirred solution of (3S,4 )-4-chlorobenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)- methyl)-3-fluoropiperidine-l-carboxylate (356 mg, 0.85 mmol) in DCM/MeOH (2 mL/2 mL) was added methanesulfonic acid in methanol (1.7 mL, 0.5 M, 0.85 mmol). The mixture was stirred for 30 min. The solution was concentrated to afford the title compound as an off-white powder (426 mg, 97%). MS (ESI) calcd for C19H20CIFN6O2: 418.1; found: 419.2[M+H]. *H NM R (400 MHz, d6-DMSO) δ 10.18 (brs, 1H), 9.36 (s, 1H), 7.93 (d, J = 4.4 Hz, 1H), 7.44 (d, J = 8.0 Hz, 2H), 7.38 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 4.4 Hz, 1H), 5.07 (s, 2H), 4.95- 4.75 (m, 1H), 4.36-4.23 (m, 1H), 4.14-4.03 (m, 1H), 3.67- 3.37 (m, 2H), 3.15-2.72 (m, 2H), 2.35 (s, 3H), 2.30-2.11 (m, 1H), 1.70-1.58 (m, 1H), 1.49-1.36 (m, 1H).
EXAMPLE 1.8. (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-2.4).
Figure imgf000169_0002
[0209] To a solution of (4-fluorophenyl)methanol (65 mg, 0.51 mmol) in dried DMSO (3 mL) was added CDI (90 mg, 0.56 mmol) at room temperature. After stirring for 1.5 hr, N-(((3S,4 ?)-3- fluoropiperidin- 4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride (150 mg, 0.46 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere overnight, allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 20/1) to afford the title compound as a pale-yellow powder (101 mg, 54%). MS (ESI) calcd for C19H20F2N6O2: 402.2; found: 403.3 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 9.20 (s, 1H), 8.30- 8.28 (m, 1H), 7.75 (d, J = 4.8 Hz, 1H), 7.44-7.36 (m, 2H), 7.27 (d, J = 4.8 Hz, 1H), 7.23-7.17 (m, 2H), 5.06 (s, 2H), 4.90-4.74 (m, 1H), 4.31-4.22 (m, 1H), 4.09-4.05 (m, 1H), 3.58-3.51 (m, 1H), 3.44-3.36 (m, 1H), 3.15-2.75 (m, 2H), 2.27-2.11 (m, 1H), 1.60-1.56 (m, 1H), 1.47-1.36 (m, 1H).
EXAMPLE 1.8a. (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-2.4a).
Figure imgf000170_0001
[0210] To a solution of (3S,4 ?)-4-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (85 mg, 0.21 mmol) in DCM/MeOH (lml/lml) was added methanesulfonic acid (0.42 mL, 0.5 M, 0.21 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a pale-yellow powder (106 mg, 100%). MS (ESI) calcd for C19H20F2N6O2: 402.2; found: 403.3 [M+H]. *H NM (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.96 (d, J = 5.6 Hz, 1H), 7.43-7.36 (m, 2H), 7.24 (d, J = 5.6 Hz, 1H), 7.12-7.04 (m, 2H), 5.16-5.06 (m, 2H), 4.87-4.74 (m, 1H), 4.52-4.46 (m, 1H), 4.29-4.26 (m, 1H), 3.79-3.74 (m, 1H), 3.63-3.57 (m, 1H), 3.19-2.84 (m, 2H), 2.71 (s, 3H), 2.36-2.18 (m, 1H), 1.80-1.59 (m, 2H).
EXAMPLE 1.9. (3S,4/?)-(5-chloropyridin-2-yl)methyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate (E1-Y1.3).
Figure imgf000170_0002
[0211] To a stirred solution of (5-chloropyridin-2-yl)methanol (83 mg, 0.58 mmol) in dried DMSO (3 mL) was added CDI (102 mg, 0.63 mmol) at room temperature. After stirring for 1.5 hrs, N-(((3S,4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-8-amine dihydrochloride salt (150 mg, 0.46 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere. After stirring overnight, the mixture was allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 20/1) to afford the title compound as an off- white powder (85 mg, 39%). MS (ESI) calcd for C18H19CIFN702: 419.1; found: 420.2 [M+H]. *H NM (400 MHz, d6-DMSO) δ 9.20 (s, 1H), 8.60 (d, J = 2.0 Hz, 1H), 8.34-8.27 (m, 1H), 7.97 (dd, J = 8.0 and 2.0 Hz, 1H), 7.76 (d, J = 4.4 Hz, 1H), 7.44-7.36 (m, 1H), 7.28 (d, J = 4.4 Hz, 1H), 5.18-5.10 (m, 2H), 4.90-4.78 (m, 1H), 4.36-4.24 (m, 1H), 4.15-4.06 (m, 1H), 3.59-3.51 (m, 1H), 3.47-3.37 (m, 1H), 3.20- 2.75 (m, 2H), 2.27-2.16 (m, 1H), 1.62-1.58 (m, 1H), 1.49-1.41 (m, 1H).
EXAMPLE 1.9a. (3S,4/?)-(5-chloropyridin-2-yl)methyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate methanesulfonate (El-Y1.3a).
Figure imgf000171_0001
[0212] To a solution of (3S,4/?)-(5-chloropyridin-2-yl)methyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-8- ylamino)methyl) -3-fluoropiperidine-l-carboxylate (45 mg, 0.11 mmol) in DCM/MeOH (l mL / 1 mL) was added the methanesulfonic acid in methanol (0.11 mL, 1.0 M, 0.11 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as an off-white powder (54 mg, 100%). MS (ESI) calcd for C18H19CIFN702: 419.1; found: 420.2 [M+H]. *H NMR (400 MHz, CD3OD) 69.33 (s, 1H), 8.58 (s, 1H), 7.98-7.93 (m, 2H), 7.52 (d, J = 8.0 Hz, 1H), 7.25 (d, J = 5.6 Hz, 1H), 5.27- 5.19 (m, 2H), 4.95-4.81 (m, 1H), 4.59-4.45 (m, 1H), 4.37-4.25 (m, 1H), 3.81-3.76 (m, 1H), 3.64-3.59 (m, 1H), 3.25-2.87 (m, 2H), 2.71 (s, 3H), 2.35-2.19 (m, 1H), 1.82-1.75 (m, 1H), 1.73-1.62 (m, 1H).
EXAMPLE 1.10. (3S,4/?)-4-(fluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.7).
Figure imgf000172_0001
Step 1: methyl 4-(fluoromethyl)benzoate
Figure imgf000172_0002
[0213] To a solution of methyl 4-(hydroxymethyl)benzoate (700 mg, 4.2 mmol) in DCM (9 mL) was added DAST (1.3 mL, 11 mmol) at 0 °C. After stirring for 15 min, the mixture was warmed to room temperature. After stirring overnight at room temperature, the reaction mixture was quenched by addition of water and neutralized with solid NaHC03 at 0 °C. The aqueous layer was extracted with DCM. The combined organic layers were washed with brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (Hex/EtOAc = 5/1) to afford the title compound as a white solid (482 mg, 68%). *H NM (400 M Hz, CDCI3) δ 8.07 (d, J = 7.6 Hz, 2H), 7.44 (d, J = 7.6 Hz, 2H), 5.45 (d, J = 47.2 Hz, 2H), 3.93 (s, 3H).
Step 2: (4-(fluoromethyl)phenyl)methanol
Figure imgf000172_0003
[0214] To a suspension of LiAIH4 (34 mg, 0.89 mmol) in dried THF (2 mL) was added dropwise a solution of methyl 4-(fluoromethyl)benzoate (150 mg, 0.89 mmol) in dried THF with stirring at 0 °C. After stirring for 1 h, the mixture was quenched by addition of Na2S04 10H2O at 0 °C until no gas was evolved. After stirring at room temperature for 30 min, the reaction mixture was filtered, and the filter mass was washed with ethyl acetate. The combined filtrates were concentrated to dryness to give crude title compound (124 mg, 100%) which was used in the next step without further purification. *H NMR (400 MHz, CDCI3) δ 7.42-7.38 (m, 4H), 5.38 (d, J = 47.2 Hz, 2H), 4.73 (d, J = 6.0 Hz, 2H), 1.66 (t, 7 = 6.0 Hz, 1H). Step 3: (3S,4 ?)-4-(fluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000173_0001
[0215] To a solution of (4-(fluoromethyl)phenyl)methanol (95 mg, 0.68 mmol) in dried DMSO (4 mL) was added CDI (120 mg, 0.74 mmol) at room temperature. After stirring for 1.5 hours, A/-(((3S,4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride salt (200 mg, 0.62 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere. After stirring overnight, the mixture was diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column purification over silica gel (DCM/MeOH = 30/1) to afford the title compound as a yellow powder (117 mg, 46%). MS (ESI) calcd for C20H22F2N6O2: 416.2 ; found: 417.3 [M+H]. *H NM (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.42-7.37 (m, 4H), 7.30 (d, J = 4.8 Hz, 1H), 5.36 (d, J = 47.2 Hz, 2H), 5.20-5.10 (m, 2H), 4.88-4.74 (m, 1H), 4.52-4.41 (m, 1H), 4.30-4.22 (m, 1H), 3.68-3.63 (m, 1H), 3.60-3.55 (m, 1H), 3.15- 2.80 (m, 2H), 2.34-2.14 (m, 1H), 1.73-1.56 (m, 2H).
EXAMPLE 1.10a. (3S,4/?)-4-(fluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.7a).
Figure imgf000173_0002
[0216] To a solution of (3S,4/?)-4-(fluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)- methyl)-3-fluoropiperidine-l-carboxylate (102 mg, 0.245 mmol) in DCM/MeOH (lml/lml, v/v) was added methanesulfonic acid (0.49 mL, 0.5 M, 0.25 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a pale-yellow powder (126 mg, 100%). MS (ESI) calcd for C20H22F2N6O2: 416.18 ; found: 417.3 [M+H]. *H NM (400 MHz, CD3OD) δ 9.34 (s, 1H), 7.98 (d, J = 5.6 Hz, 1H), 7.42 (brs, 4H), 7.26 (d, J = 5.6 Hz, 1H), 5.38 (d, J=48 Hz, 2H), 5.21-5.13 (m, 2H), 4.88-4.77 (m, 1H), 4.56-4.49 (m, 1H), 4.33-4.29 (m, 1H), 3.81-3.76 (m, 1H), 3.65-3.60 (m, 1H), 3.22-2.89 (m, 2H), 2.72 (s, 3H), 2.35-2.20 (m, 1H), 1.80-1.63 (m, 2H).
EXAMPLE 1.11. (3S,4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate (El-2.6).
Figure imgf000174_0001
Step 1: methyl 4-(difluoromethyl)benzoate
Figure imgf000174_0002
[0217] To a stirred solution of methyl 4-formylbenzoate (10.0 g, 61 mmol) in DCM (300 mL) was added DAST (16 mL, 121 mmol) dropwise at 0 °C. The reaction mixture was stirred overnight at room temperature and quenched by addition of saturated sodium bicarbonate solution. The mixture was extracted with DCM. The combined organic phases were washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: hexane/EtOAc = 10:1) to afford the title compound as a yellow powder (9.26 g, 81%). 1H NMR (400 MHz, CDCI3) δ 8.13 (d, J = 8.0 Hz, 1H), 7.59 (d, J = 8.0 Hz, 1H), 6.69 (t, J = 56.4 Hz, 1H), 3.95 (s, 3H).
Step 2. (4-(difluoromethyl)phenyl)methanol
Figure imgf000174_0003
[0218] A solution of methyl 4-(difluoromethyl)benzoate (1.00 g, 5.37 mmol) in THF (dried) was added dropwise to a stirred suspension of LiAIH4 in dry THF (25 mL) at 0 °C under N2 atmosphere. The reaction mixture was stirred for 1 h, then quenched by addition of Na2SO4.10H2O under ice-water bath cooling. The mixture was stirred at rt for 30 min and filtered through celite. The filter mass was washed with EtOAc. The combined organic phases were dried over Na2S04, and concentrated in vacuo to afford the title compound as a white solid (650 mg, 77%). 1H NM (400 MHz, CDCI3) δ 7.51 (d, J = 8.0 Hz, 1H), 7.46 (d, J = 8.0 Hz, 1H), 6.65 (t, J = 56.4 Hz, 1H), 4.75 (d, J = 6.0 Hz, 2H), 1.78 (t, J=6.0 hz, 1H).
Step 3. (3S,4R)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000175_0001
[0219] To a stirred solution of (4-(difluoromethyl)phenyl)methanol (236 mg, 1.49 mmol) in DMSO (7.5 mL) was added CDI (224 mg, 1.38 mmol) at room temperature. After stirring for lh, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine dihydrochloride salt (330 mg, 1.15 mmol) was added. The mixture was heated to 50°C in a sealed tube under N2 atmosphere overnight. The mixture was allowed to cool to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (eluent: DCM/MeOH = 50:1) to afford the title compound as a yellow powder (188 mg, 38%). MS (ESI) calcd for C20H21F3N6O2: 434.2; found: 435.2[M+H]. 1H NMR (400 M Hz, C/6-DMSO) δ 9.20 (s, 1H), 8.29 (t, J = 4.4 Hz, 1H), 7.75 (d, J = 4.4 Hz, 1H), 7.57(d, J = 8.0 Hz, 2H), 7.48 (d, J = 8.0 Hz, 2H), 7.27 (d, J = 4.4 Hz, 1H), 7.03 (t, J = 56.4 Hz, 1H), 5.14 (s, 2H), 4.92- 4.74 (m, 1H), 4.33- 4.23 (m, 1H), 4.13- 4.05 (m,lH), 3.58-3.48 (m, 1H), 3.45-3.35 (m, 1H), 3.19-2.14 (m, 2H), 2.27-2.12 (m, 1H), 1.62-1.54 (m, 1H), 1.49-1.37 (m,lH).
EXAMPLE 1.11a. (3S,4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.6a).
Figure imgf000176_0001
CH3SO3H
[0220] To a stirred solution of (3S,4 )-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (188 mg, 0.43 mmol) in MeOH (3 mL) was added methanesulfonic acid in methanol (0.87 mL, 0.5 M, 0.43 mmol). The mixture was stirred for 30 min, then concentrated to afford the title compound as an off-white powder (220 mg, 100%). MS (ESI) calcd for C20H21F3N6O2: 434.2; found: 435.2[M+H]. *H NM R (400 MHz, CD3OD) δ 9.32 (s, IH), 7.96 (d, J = 5.6 Hz, IH), 7.56-7.48 (m, 4H), 7.24 (d, J = 5.6 Hz, IH), 6.76 (t, J = 56.4 Hz, IH), 5.21 (s, 2H), 4.96- 4.90 (m, IH), 4.57- 4.45 (m, IH), 4.35- 4.25 (m, IH), 3.80-3.75 (m, IH), 3.64-3.58 (m, IH), 3.23-2.87 (m, 2H), 2.71 (s, 3H), 2.37-2.20 (m, IH), 1.80-1.63 (m, 2H).
EXAMPLE 1.12. (3S,4 ?)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-2.5).
Figure imgf000176_0002
[0221] To a stirred solution of (4-ethylphenyl)methanol (93 mg, 0.68 mmol) in dry DMSO (4 mL) was added CDI (120 mg, 0.74 mmol) at room temperature. After stirring for 1.5 hr, N-(((3S,4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride salt (200 mg, 0.62 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere overnight. After allowing to cool to room temperature, the mixture was diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 20/1) to afford the title compound as a pale-yellow powder (124 mg, 48%). MS (ESI) calcd for C21H25FN602: 412.2; found: 413.3 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, IH), 7.69 (d, J = 4.8 Hz, IH), 7.30 (d, J = 4.8 Hz, IH), 7.26 (d, J = 8.0 Hz, 2H), 7.19 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.90-4.72 (m, 1H), 4.50-4.40 (m, 1H), 4.28-4.21 (m, 1H), 3.68- 3.62 (m, 1H), 3.59-3.54 (m, 1H), 3.15-2.79 (m, 2H), 2.64 (q, J = 7.6 Hz, 2H), 2.30-2.12 (m, 1H), 1.73- 1.49 (m, 2H), 1.22 (t, J = 7.6 Hz, 3H).
EXAMPLE 1.12a. (3S,4 ?)-4-ethyl benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate mesylate (El-2.5a).
Figure imgf000177_0001
[0222] To a stirred solution of (3S,4 ?)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)- methyl)-3-fluoropiperidine -1-carboxylate (106 mg, 0.26 mmol) in DCM/MeOH (1 mL / lmL) was added methanesulfonic acid in methanol (0.52 mL, 0.5 M, 0.26 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a pale-yellow powder (130 mg, 100%). MS (ESI) calcd for C21H25FN602: 412.2 ; found: 413.3 [M+H].. *H NM (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.95 (d, J = 5.6 Hz, 1H), 7.28 (d, J = 8.0 Hz, 2H), 7.26 (d, J = 5.6 Hz, 1H), 7.21 (d, J = 8.0 Hz, 2H), 5.10 (s, 2H), 4.88-4.74 (m, 1H), 4.54-4.48 (m, 1H), 4.31-4.23 (m, 1H), 3.81-3.74 (m, 1H), 3.63-3.58 (m, 1H), 3.20-2.83 (m, 2H), 2.72 (s, 3H), 2.64 (q, J = 7.6 Hz, 2H), 2.37-2.18 (m, 1H), 1.79-1.58 (m, 2H), 1.22 (t, J = 7.6 Hz, 3H).
EXAMPLE 1.13. (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-2.15).
Figure imgf000177_0002
Step 1: (2-fluoro-4-methylphenyl)methanol
Figure imgf000178_0001
[0223] A solution of 2-fluoro-4-methylbenzoic acid (500 mg, 0.32 mmol) in dry THF (10 mL) was added dropwise to a stirred suspension of LiAIH4 (120 mg, 0.32 mmol) in dry THF (10 mL) at 0 °C under N2 atmosphere. After stirring for 1 hr, the mixture was quenched by addition of Na2S04 10H2O at 0 °C. The mixture was stirred at r.t for additional 30 min, then filtered through celite. The filter mass was extracted with EtOAc, and the combined filtrates were concentrated. The residue was purified by column chromatography over silica gel (Hex/EtOAc = 5/1) to afford the title compound as a colorless oil (182 mg, 40%). *H NM (400 MHz, CDCI3) δ 7.29 (d, J = 8.0 Hz, 1H), 6.95 (d, J = 8.0 Hz, 1H), 6.88 (d, J = 11.2 Hz, 1H), 4.74-4.68 (m, 2H), 2.35 (s, 3H), 1.70 (brs, 1H).
Step 2: (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000178_0002
[0224] To a stirred solution of (2-fluoro-4-methylphenyl)methanol (143 mg, 1.02 mmol) in dried DMSO (6 mL) was added CDI (180 mg, 1.11 mmol) at room temperature. After stirring for 1.5 hrs, A/-(((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride salt (300 mg, 0.93 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere with stirring overnight. The mixture was allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 40/1) to afford the title compound as a pale-yellow powder (160 mg, 42%). MS (ESI) calcd for C20H22F2N6O2: 416.2; found: 417.3 [M+HJ H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.32-7.26 (m, 2H), 6.99 (d, J = 7.6 Hz, 1H), 6.94 (d, J = 11.2 Hz, 1H), 5.17-5.10 (m, 2H), 4.87-4.71 (m, 1H), 4.50-4.36 (m, 1H), 4.27-4.17 (m, 1H), 3.67-3.62 (m, 1H), 3.59-3.54 (m, 1H), 3.14-2.80 (m, 2H), 2.34 (s, 3H), 2.29- 2.12 (m, 1H), 1.72-1.57 (m, 2H). EXAMPLE 1.13a. (3S,4 ?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate mesylate (El-2.15a).
Figure imgf000179_0001
CH3S03H
[0225] To a stirred solution of (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (150 mg, 0.36 mmol) in DCM/MeOH (2 mL / 1 mL) was added methanesulfonic acid in methanol (0.72 mL, 0.5 M, 0.36 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a pale-yellow powder (160 mg, 100%). MS (ESI) calcd for C20H22F2N6O2: 416.2 ; found: 417.3 [M+H]. *H NM (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.96 (d, J = 5.6 Hz, 1H), 7.29 (t, J = 8.0 Hz, 1H), 7.24 (d, J = 5.6 Hz, 1H), 6.99 (d, J = 8.0 Hz, 1H), 6.94 (d, J = 11.2 Hz, 1H), 5.15 (s, 2H), 4.88-4.73 (m, 1H), 4.54-4.40 (m, 1H), 4.31-4.20 (m, 1H), 3.79- 3.74 (m, 1H), 3.63-3.57 (m, 1H), 3.18-2.84 (m, 2H), 2.70 (s, 3H), 2.35 (s, 3H), 2.33-2.19 (m, 1H), 1.79- 1.58 (m, 2H).
EXAMPLE 1.14. (3S,4/?)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-2.8).
Figure imgf000179_0002
[0226] To a stirred solution of (4-(trifluoromethyl)phenyl)methanol (150 mg, 0.85 mmol) in dried DMSO (5 mL) was added CDI (150 mg, 0.93 mmol) at room temperature. After stirring for 1.5 hrs, N- (((3S,4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride salt (250 mg, 0.77 mmol) was added. The mixture was heated to 50 °C under N2 atmosphere with stirring overnight. The mixture was allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 30/1) to afford the title compound as an off-white powder (150 mg, 43%). MS (ESI) calcd for C2oH2oF4N602: 452.2 ; found: 453.2 [M+H]. *H NM (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.70 (d, J = 4.8 Hz, 1H), 7.66 (d, J = 8.0 Hz, 2H), 7.55 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 4.8 Hz, 1H), 5.28-5.16 (m, 2H), 4.93-4.77 (m, 1H), 4.55-4.42 (m, 1H), 4.33-4.22 (m, 1H), 3.69-3.62 (m, 1H), 3.60-3.55 (m, 1H), 3.17-2.82 (m, 2H), 2.31-2.15 (m, 1H), 1.74-1.52 (m, 2H).
EXAMPLE 1.14a. (3S,4/?)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.8a).
Figure imgf000180_0001
[0227] To a stirred solution of (3S,4/?)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (130 mg, 0.29 mmol) in DCM/MeOH (2 mL / lmL) was added methanesulfonic acid in methanol (0.58 mL, 0.5 M, 0.29 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as pale-yellow powder (155 mg, 98%). MS (ESI) calcd for C20H20F4N6O2: 452.2 ; found: 453.2 [M+H]. *H NM R (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.96 (d, J = 5.6 Hz, 1H), 7.66 (d, J = 8.0 Hz, 2H), 7.56 (d, J = 8.0 Hz, 2H), 7.24 (d, J = 5.6 Hz, 1H), 5.28-5.17 (m, 2H), 4.96-4.76 (m, 1H), 4.59-4.45 (m, 1H), 4.37-4.23 (m, 1H), 3.80-3.75 (m, 1H), 3.64- 3.59 (m, 1H), 3.23-2.87 (m, 2H), 2.71 (s, 3H), 2.38-2.20 (m, 1H), 1.81-1.60 (m, 2H).
EXAMPLE 1.15. (3S,4/?)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-1.8).
Figure imgf000180_0002
[0228] To a stirred solution of (4-(trifluoromethyl) phenyl)methanol (335 mg, 1.9 mmol) in DMSO (10 mL) was added CDI (238 mg, 1.47 mmol) at room temperature. After stirring for lh, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride salt (350 mg, 1.05 mmol) was added. The mixture was heated at 50°C in a sealed tube under N2 atmosphere overnight. The mixture was allowed to cool to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated in vacuo. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 50:1) to afford the title compound as a yellow powder (270 mg, 63%). MS (ESI) calcd for C2oH2oF4N602: 452.2; found: 453.2[M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.72 (d, J = 4.8 Hz, 1H), 7.66 (d, J = 8.0 Hz, 2H), 7.56 (d, J = 8.0 Hz, 2H), 7.32 (d, J = 4.8 Hz, 1H), 5.29-5.18 (m, 2H), 4.90-4.76 (m, 1H), 4.55-4.40 (m, 1H), 4.32-4.20 (m, 1H), 3.69 -3.55 (m, 2H), 3.18-3.01 (m, 1H), 2.99-2.82 (m, 1H), 2.34-2.14 (m, 1H), 1.75-1.51 (m, 2H).
EXAMPLE 1.15a. (3S,4/?)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-1.8a).
Figure imgf000181_0001
[0229] To a solution of (3S,4R)-4-(trifluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)- methyl)-3-fluoropiperidine-l-carboxylate (270 mg, 0.64 mmol) in MeOH (3 mL) was added methanesulfonic acid in methanol (1.28 mL, 0.5 M, 0.64mmol). The mixture was stirred for 30 min, then concentrated in vacuo to afford the title compound as an off-white powder (297 mg, 91%). MS (ESI) calcd for C20H20F4N6O2: 452.2; found: 453.2[M+H]. *H NM R (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.95 (d, J = 5.6 Hz, 1H), 7.65 (d, J = 8.0 Hz, 2H), 7.56 (d, J = 8.0 Hz, 2H), 7.25 (d, J = 5.6, 1H), 5.30-5.15 (m, 2H), 4.95-4.77 (m, 1H), 4.60-4.45 (m, 1H), 4.37-4.23 (m, 1H), 3.80-3.75 (m, 1H), 3.64-3.59 (m, 1H), 3.23-2.86 (m, 2H), 2.71 (s, 3H), 2.38-2.20 (m, 1H), 1.82-1.60 (m, 2H).
EXAMPLE 1.16. (3S,4 ?)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-1.5).
Figure imgf000181_0002
[0230] To a stirred solution of (4-ethylphenyl)methanol (223 mg, 1.64 mmol) in DMSO (6 mL) was added CDI (204 mg, 1.26 mmol) at room temperature. After stirring for lh, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride (300 mg, 0.93 mmol) was added. The stirred mixture was heated to 50°C in the sealed tube under N2 atmosphere overnight. The mixture was allowed to cool down to and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated.The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 50/1) to afford the title compound as a yellow powder (200 mg, 52%). MS (ESI) calcd for C2iH25FN602: 412.2; found: 413.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.30 (d, J = 4.8 Hz, 1H), 7.26 (d, J = 8.0 Hz, 2H), 7.19 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.87-4.71 (m, 1H), 4.50-4.40 (m, 1H), 4.28-4.20 (m, 1H), 3.66-3.54 (m, 2H), 3.13-2.77 (m, 2H), 2.63 (q, J = 7.6 Hz, 2H), 2.30-2.12 (m, 1H), 1.73-1.55 (m, 2H), 1.21 (t, J = 7.6 Hz, 3H).
EXAMPLE 1.16a. (3S,4 ?)-4-ethyl benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-1.5a).
Figure imgf000182_0001
CH3S03H
[0231] To a stirred solution of (3S,4R)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)- methyl)-3-fluoropiperidine-l-carboxylate (200 mg, 0.48 mmol) in MeOH (3 mL) was added the 0.5M methanesulfonic acid in methanol (0.97 mL, 0.48 mmol). After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (225 mg, 91%). MS (ESI) calcd for C21H25FN602: 412.2; found: 413.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.31 (s, 1H), 7.94 (d, J = 4.8 Hz, 1H), 7.27 (d, J = 8.0 Hz, 2H), 7.23 (d, J = 4.8 Hz, 1H), 7.19 (d, J = 8.0 Hz, 2H), 5.09 (s, 2H), 4.85-4.75 (m, 1H), 4.54-4.44 (m, 1H), 4.31-4.24 (m, 1H), 3.81-3.72 (m, 1H), 3.65-3.56 (m,lH), 3.17-2.88 (m, 2H), 2.70 (s, 3H), 2.64 (q, J = 7.6 Hz, 2H), 2.36-2.20 (m, 1H), 1.77-1.62 (m, 2H),1.22 (t, J = 7.6 Hz, 3H).
EXAMPLE 1.17. (3S,4 ?)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate (El-2.11).
Figure imgf000183_0001
Step 1: methyl 4-cyclopropylbenzoate
Figure imgf000183_0002
[0232] A mixture of methyl 4-bromobenzoate (5.05 g, 23.6 mmol), cyclopropylboronic acid (10.0 g , 0.12 mol), Pd(PPh3)4 (2.7 g, 2.34 mmol) and saturated sodium carbonate (30 mL, 46 mmol) in DME (100 mL) was heated to 95°C in the sealed tube under N2 atmosphere. After stirring overnightthe mixture was cooled to rt and concentrated. The concentrate was partitioned into DCM and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated in vacuo. The concentrate was purified by column chromatography over silica gel (hexane/DCM = 10/1) to afford the title compound as a yellow oil (710 mg, 17%). MS (ESI) calcd for CnHi202: 176.0; found: 177.3[M+H]. *H NM (400 MHz, CDCI3) δ 7.91 (d, J = 8.0 Hz, 2H), 7.10(d, J = 8.0 Hz, 2H), 3.89 (s, 3H), 1.97-1.90 (m, 1H), 1.08-1.02 (m, 2H), 0.80-0.74 (m, 2H).
Step 2: (4-cyclopropylphenyl)methanol
Figure imgf000183_0003
[0233] A solution of methyl 4-cyclopropylbenzoate (710 mg, 4.0 mmol) in dry THF was added dropwise to a suspension of LiAIH4 in THF (20 mL) at 0 °C under N2 atmosphere. The reaction mixture was stirred for lh, then quenched by addition of Na2SO4.10H2O under ice-water bath cooling. The mixture was stirred at rt for 30 min, and filtered through celite. The filter mass was extracted with EtOAc. The combined filtrate and organic extracts were dried over Na2S04 and concentrated to afford the title compound as a brown oil (500 mg, 83%). H NM (400 M Hz, CDCI3) δ 7.26 (d , J Hz, 2H), 7.07 (d, J = 8.0 Hz, 2H), 4.64 (s, 2H), 1.94-1.85 (m, 1H), 0.98-0.93 (m, 2H), 0.70-0.66 (m,
Step 3: (3S,4R)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000184_0001
[0234] To a stirred solution of (4-cyclopropylphenyl)methanol (200 mg, 1.37 mmol) in DMSO (5 mL) was added CDI (160 mg, 1.26 mmol) at room temperature. After stirring for 1 hr, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine dihydrochloride salt (300 mg, 1.05 mmol) was added. The mixture was heated at 50°C in a sealed tube under N2 atmosphere overnight. The mixture was allowed to cool to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH 50:1) to afford the title compound as a yellow powder (160 mg, 36%). MS (ESI) calcd for C22H25FN602: 424.2; found: 425.0[M+H]. *H NMR (400 MHz, d6-DMSO) δ 9.20 (s, 1H), 8.29 (t, J = 5.6 Hz, 1H), 7.75 (d, J = 4.8 Hz, 1H), 7.27 (d, J = 4.8 Hz, 1H), 7.22 (d, J = 8.0 Hz, 2H), 7.06 (d, J = 8.0 Hz, 2H), 5.00 (s, 2H), 4.90-4.72 (m, 1H), 4.32- 4.18 (m, 1H), 4.12- 4.00 (m, 1H), 3.59-3.48 (m, 1H), 3.44-3.35 (m, 1H), 3.13-2.72 (m, 2H), 2.28-2.10 (m, 1H), 1.94- 1.86 (m,lH), 1.61-1.52 (m, 1H), 1.47-1.34 (m, 1H), 0.96- 0.90 (m, 2H), 0.67- 0.62 (m, 2H).
EXAMPLE 1.17a. (3S,4 ?)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.11a).
Figure imgf000184_0002
[0235] To a stirred solution of (3S,4 )-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (150 mg, 0.34 mmol) in MeOH (3 mL) was added methanesulfonic acid in methanol (0.68 mL, 0.5 M, 0.34 mmol). The mixture was stirred for 30 min, then concentrated in vacuo to afford the title compound as an off-white powder (155 mg, 86%). MS (ESI) calcd for C22H25FN602: 424.2; found: 425.3[M+H]. *H NMR (400 MHz,CD3OD) δ 9.32 (s, IH), 7.96 (d, J = 5.6 Hz, IH), 7.26 (d, J = 5.6 Hz, IH), 7.23 (d, J = 8.0 Hz, 2H), 7.06 (d, J = 8.0 Hz, 2H), 5.07 (s, 2H), 4.90- 4.76 (m, IH), 4.54-4.43 (m, IH), 4.31-4.23 (m, IH), 3.80-3.75 (m, IH), 3.64-3.58 (m, IH), 3.17- 2.82 (m, 2H), 2.70 (s, 3H), 2.37-2.17 (m, IH), 1.94-1.86 (m, IH), 1.79-1.61 (m, 2H), 0.96- 0.90 (m, 2H), 0.67-0.62 (m, 2H).
EXAMPLE 1.18. (3S,4 ?)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-1.11).
Figure imgf000185_0001
[0236] To a solution of (4-cyclopropylphenyl) methanol (200 mg, 1.37 mmol) in DMSO (5 mL) was added CDI (160 mg, 1.26 mmol) at room temperature. After stirring for 1 h, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-5-amine dihydrochloride salt (300 mg, 1.05 mmol) was added. The mixture obtained was heated to 50°C in a sealed tube under N2 atmosphere. After stirring overnight, the mixture was cooled down to rt and partitioned into ethylacetate and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH=50:l) to afford the title compound as a yellow powder (140 mg, 35%). MS (ESI) calcd for C22H25FN602: 424.2; found: 425.3 [M+H]. IH NMR (400 MHz, d6-DMSO) δ 9.09 (s, IH), 7.69 (d, J = 4.8 Hz, IH), 7.30 (d, J = 4.8 Hz, IH), 7.23 (d, J = 8.0 Hz, 2H), 7.06 (d, J = 8.0 Hz, 2H), 5.06 (s, 2H), 4.89- 4.73(m, IH), 4.50- 4.39(m, IH), 4.27-4.18 (m, IH), 3.67-3.54 (m, 2H), 3.14-2.77 (m, 2H), 2.30-2.10 (m, IH), 1.93-1.86 (m, IH), 1.73-1.54 (m, 2H), 0.99-0.90 (m, 2H), 0.70-0.66 (m, 2H).
EXAMPLE 1.18a. (3S,4 ?)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-l.lla).
Figure imgf000186_0001
CH3S03H
[0237] To a solution of (3S,4R)-4-cyclopropylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)- 3-fluoropiperidine-l-carboxylate (110 mg, 0.34 mmol) in MeOH (3 mL) was added methanesulfonic acid in methanol (0.68 mL, 0.5M, 0.34mmol). The mixture was stirred for 30min and concentrated in vacuo to afford the title compound as an off-white powder (120 mg, 84%). MS (ESI) calcd for C22H25FN602: 424.2; found: 425.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.95 (d, J = 4.8 Hz, 1H), 7.24 (d, J = 4.8 Hz, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.05 (d, J = 8.0 Hz, 2H), 5.07 (s, 2H), 4.86-4.74 (m, 1H), 4.55-4.42 (m, 1H), 4.32-4.23 (m, 1H), 3.79-3.74 (m, 1H), 3.63-3.57 (m, 1H), 3.17-2.83 (m, 2H), 2.70 (s, 3H), 2.37-2.17 (m,lH), 1.93-1.87 (m, 1H), 1.80-1.60 (m, 2H), 0.98- 0.94 (m, 2H), 0.68-0.64 (m, 2H).
EXAMPLE 1.19. (3S,4 ?)-4-chloro-2-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-2.14).
Figure imgf000186_0002
Step 1: (4-chloro-2-fluorophenyl)methanol
Figure imgf000186_0003
[0238] To a stirred suspension of LiAIH4 (110 mg, 2.88 mmol) in dried THF (10 mL) was added dropwise a solution of methyl 4-chloro-2-fluoromethylbenzoate (500 mg, 2.88 mmol) in dried THF (10 mL) at 0 °C under N2 atmosphere. After stirring for 1 h, the mixture was quenched by addition of Na2S04 10H2O at 0 °C. The mixture was stirred at r.t for30 min and subsequently filtered through celite. The filter pad was extracted with ethyl acetate, and the total filtrate was concentrated. The concentrate was purified by column chromatography over silica gel (Hex/EtOAc = 20/1) to afford the title compound as a yellow oil (378mg, 82%). *H NM (400 MHz, CDCI3) δ 7.38 (t, J = 8.0 Hz, 1H), 7.15 (dd, J = 8.0 and 2.0 Hz, 1H), 7.09 (dd, J = 10.0, 2.0 Hz, 1H), 4.73 (d, J = 6.0 Hz, 2H), 1.82 (t, J = 6.0 Hz, 1H).
Step 2: (3S,4 ?)-4-chloro-2-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000187_0001
[0239] To a solution of (4-chloro-2-fluorophenyl)methanol (136 mg, 0.85 mmol) in dried DMSO (5 mL) was added CDI (145 mg, 0.93 mmol) at room temperature. After stirring for 1.5 hrs, A/-(((3S,4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-5-amine dihydrochloride salt (250 mg, 0.77 mmol) was added. The reaction mixture was heated to 50 °C under N2 atmosphere, overnight. The mixture was allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 30/1) to afford the title compound as a pale- yellow powder (140 mg, 42%). MS (ESI) calcd for C19H19CIF2N602: 436.1 ; found: 437.2 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.43 (t, J = 8.0 Hz, 1H), 7.30 (d, J = 4.8 Hz, 1H), 7.26-7.20 (m, 2H), 5.21-5.12 (m, 2H), 4.88-4.73 (m, 1H), 4.48-4.39 (m, 1H), 4.26-4.29 (m, 1H), 3.67-3.62 (m, 1H), 3.59-3.54 (m, 1H), 3.14-2.81 (m, 2H), 2.31-2.15 (m, 1H), 1.72-1.54 (m, 2H).
EXAMPLE 1.19a. (3S,4 ?)-4-chloro-2-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-2.14a).
Figure imgf000187_0002
[0240] To a solution of (3S,4 ?)-4-chloro-2-fluorobenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-5-ylamino)- methyl)-3- fluoropiperidine-l-carboxylate (120 mg, 0.27 mmol) in DCM/MeOH (2 mL / 1 m L) was added methanesulfonic acid in methanol (0.54 m L, 0.5M, 0.27 mmol). The mixture was stirred for 15 min, and concentrated to afford the title compound as a pale-yellow powder (145 mg, 100%). MS (ESI) calcd for C19H19CIF2N602: 436.1 ; found: 437.2 [M+H]. *H N M (400 M Hz, CD3OD) δ 9.32 (s, 1H), 7.95 (d, J = 6.0 Hz, 1H), 7.47-7.39 (m, 1H), 7.27-7.17 (m, 3H), 5.21-5.12 (m, 2H), 4.88-4.73 (m, 1H), 4.51-4.41 (m, 1H), 4.29-4.21 (m, 1H), 3.79-3.74 (m, 1H), 3.63-3.57 (m, 1H), 3.18-2.86 (m, 2H), 2.70 (s, 3H), 2.32-2.18 (m, 1H), 1.77-1.57 (m, 2H).
EXAM PLE 1.20. (3S,4 ?)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-o] pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-6.5).
Figure imgf000188_0001
[0241] To a stirred solution of (4-ethylphenyl)methanol (101 mg, 0.75 mmol) in DMSO (3 mL) was added CDI (131 mg, 0.81 mmol) at room temperature. After stirring for lh, N-(((3S, 4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyridin-3-amine dihydrochloride (200 mg, 0.62 mmol) was added. The mixture was heated to 50°C in the sealed tube under N2 atmosphere. After stirring overnight, the mixture was cooled down to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 20:1) to afford the title compound as an off-white powder (122 mg, 48%). MS (ESI) calcd for C22H26FN502: 411.2; found: 412.6 [M+H]. 1H NM R (400 M Hz, CD3OD) δ 8.00 (d, J = 6.8 Hz, 1H), 7.43 (d, J = 9.2 Hz, 1H), 7.27 (d, J = 8.0 Hz, 2H), 7.22 (dd, J = 9.2, 6.8 Hz, 1H), 7.19 (d, J = 8.0 Hz, 2H), 6.80 (t, J = 9.2 Hz, 1H), 5.08 (s, 2H), 4.95-4.78 (m, 1H), 4.51-4.41 (m, 1H), 4.29-4.21 (m, 1H), 3.58-3.52 (m, 1H), 3.47-3.42 (m, 1H), 3.11- 2.82 (m, 2H), 2.64 (q, J = 7.6 Hz, 2H), 2.29-2.12 ( m, 1H ), 1.74-1.66 (m, 1H), 1.63-1.52 (m, 1H), 1.22 (t, 7 = 7.6 Hz, 3H).
EXAM PLE 1.20a. (3S,4 ?)-4-ethyl benzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-6.5a).
Figure imgf000189_0001
CH3S03H
[0242] To a solution of (3S, 4 ?)-4-ethylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate (117 mg, 0.29 mmol) in MeOH (4 mL) was added methylsulfonic acid in MeOH (0.285 mL, 1.0M, 0.29 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as a white powder (140 mg, 96%). MS (ESI) calcd for C22H26FN502:411.2; found: 412.7 [M+H]. 1H NM (400 MHz, CD3OD) δ 8.46 (d, J = 7.2 Hz, 1H), 7.90 (dd, J = 9.2 and 7.2 Hz, 1H), 7.79 (d, J = 9.2 Hz, 1H), 7.36 (t, J = 7.2 Hz, 1H), 7.27 (d, J = 8.0 Hz, 2H), 7.19 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.95-4.78 (m, 1H), 4.51-4.44 (m, 1H), 4.29-4.24 (m, 1H), 3.63-3.58 (m, 1H), 3.51-3.46 (m, 1H), 3.14-2.83 (m, 2H), 2.70 (s, 3H), 2.64 (q, J = 7.6 Hz, 2H), 2.32-2.16 ( m, 1H ), 1.73-1.55 (m, 2H), 1.22 (t, J = 7.6 Hz, 3H).
EXAMPLE 1.21. (3S,4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-6.6).
Figure imgf000189_0002
Step 1: (3S,4/?)-ferf-butyl 3-fluoro-4-((2-(pyridin-2-yl)hydrazinecarboxamido)methyl) piperidine- 1-carboxylate
Figure imgf000189_0003
[0243] A solution of (3S, 4/?)-ferf-butyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate (500 mg, 2.16 mmol) in dichloromethane (2 mL) was added to a solution of triphosgene (216 mg, 0.73 mmol) in dichloromethane (4 mL) at 0 °C under nitrogen. Triethylamine (0.57 mL, 4.12 mmol) in dichloromethane (2 mL) was added dropwise, and the mixture was stirred at room temperature. After stirring for 2 hours, the mixture was cooled to 0 °C and a solution of 2-hydrazinylpyridine (224 mg, 2.06 mmol) in dichloromethane (4 m L) was then added. The mixture was stirred overnight at room temperature and diluted with dichloromethane. The organic phase was washed with saturated NaHC03, brine, dried over Na2S04 and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (4% MeOH-DCM) to afford the title compound as a yellow powder (400 mg, 53 %). MS (ESI) calcd for C17H26FN5O3: 367.4; found: 368.6 [M+H]. *H N M (400 M Hz, CD3OD) δ 8.07 (d, J = 5.2 Hz, 1H), 7.65-7.61 (m, 1H), 6.82 (d, J = 5.6, 5.2 Hz, 1H), 6.77 (d, J = 8.4 Hz, 1H), 4.72-4.54 (m, 1H), 4.37-4.28 (m, 1H), 4.16-4.10 (m, 1H), 3.27-3.22 (m, 1H), 3.18-3.13 (m, 1H), 3.00-2.65 (m, 2H), 1.95-1.79 ( m, 1H ), 1.54-1.46 (m, 2H), 1.44 (s, 9H).
Step 2: (3S, 4/?)-ferf-butyl 4-(([l,2,4]triazolo[4,3-a]pyridin-3-ylamino)methyl)-3-fluoropiperidine- 1-carboxylate
Figure imgf000190_0001
4] Hexachloroethane (1.01 g, 4.31 mmol) was added portionwise to a stirred solution of triphenylphosphine (1.13 g, 4.31 mmol) and triethylamine (1.16 ml, 8.61 mmol) in dry TH F (8 mL) at room temperature. After stirring overnight, the resulting suspension was filtered through celite, and the filtrate was concentrated in vacuo. The residue was dissolved in ethylacetate, and the solution was washed with water, brine, dried over Na2S04 and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (3% MeOH-DCM) to afford the title compound as an off-white powder (220 mg, 59%). MS (ESI) calcd for C17H24FN5O2: 349.2; found: 350.2 [M+H]. *H N M R (400 M Hz, CD3OD) δ 8.01 (d, J=7.2 Hz, 1H), 7.43 (d, J=9.2 Hz, 1H), 7.25-7.21 (m, 1H), 6.83-6.79 (m, 1H), 4.92-4.77 (m, 1H), 4.43-4.36 (m, 1H), 4.24-4.15 (m, 1H), 3.58-3.52 (m, 1H), 3.46-3.41 (m, 1H), 3.04-2.70 (m, 2H), 2.27-2.10 ( m, 1H ), 1.72-1.64 (m, 1H), 1.62-1.51 (m, 1H), 1.46 (s, 9H).
Step 3: N-(((3S, 4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]-pyridin-3-amine
dihydrochloride
Figure imgf000191_0001
[0245] To a solution of (3S,4/?)-ferf-butyl 4-(([l,2,4]triazolo[4,3-a]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (220 mg, 0.63 mmol) in MeOH (5 mL) was added HCI in ether (5 mL, 1.0 M) at room temperature. After stirring overnight, the mixture was concentrated to afford the title compound as an off-white powder (209 mg, 100%) which was used directly in the next step without further purification. MS (ESI) calcd for C12H16FN5: 249.1; found: 250.3 [M+H].
Step 4: (3S, 4/?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000191_0002
[0246] To a stirred solution of (4-(difluoromethyl)phenyl)methanol (118 mg, 0.75 mmol) in DMSO (3 mL) was added CDI (131 mg, 0.81 mmol) at room temperature. After stirring for lh, A/-(((3S, 4 ?)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo-[4,3-o]pyridin-3-amine dihydrochloride (200 mg, 0.62 mmol) was added. The mixture was heated to 50 °C in the sealed tube under N2 atmosphere. After stirring overnight, the mixture was cooled down to rt and partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: DCM/MeOH = 15:1) to afford the title compound as an off-white powder (140 mg, 52%). MS (ESI) calcd for C2iH22F3N502:433.2; found: 434.6 [M+H]. 1H NM (400 MHz, CD3OD) δ 8.03 (d, J=7.2 Hz, 1H), 7.53 (d, J = 8.0 Hz, 2H), 7.48 (d, J = 8.0 Hz, 2H), 7.45 (d, J=9.2 Hz, 1H), 7.25-7.20 (m, 1H), 6.84-6.80 (m, 1H), 6.76 (t, J = 56.0 Hz, 1H), 5.23- 5.14 (m, 2H), 4.97-4.79 (m, 1H), 4.53-4.44 (m, 1H), 4.32-4.23 (m, 1H), 3.59-3.51 (m, 1H), 3.47-3.42 (m, 1H), 3.15-2.83 (m, 2H), 2.30-2.14 ( m, 1H ), 1.76-1.68 (m, 1H), 1.65-1.54 (m, 1H). EXAMPLE 1.21a. (3S,4 ?)-4-(difluoromethyl)benzyl-4-(([l,2,4]triazolo[4 -o]-pyridin-3-ylamino fluoropiperidine-l-carboxylate methanesulfonate (El-6.6a).
Figure imgf000192_0001
CH3SO3H
[0247] To a stirred solution of ((3S, 4 ?)-4-(difluoromethyl)benzyl 4-(([l,2,4]triazolo[4,3-o]-pyridin-3- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (136 mg, 0.31 mmol) in MeOH (4 mL) was added methylsulfonic acid in MeOH (0.314 mL, 1.0 M, 0.31 mmol). The reaction mixture was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as a white powder (156 mg, 94%). MS (ESI) calcd for C21H22F3N502:433.2; found: 434.6 [M+H]. 1H NM (400 MHz, CD3OD) δ 8.46 (d, J = 7.2 Hz, 1H), 7.91 (dd, J = 9.2 and 7.2 Hz, 1H), 7.80 (d, J = 9.2 Hz, 1H), 7.54 (d, J = 8.0 Hz, 2H), 7.48 (d, J = 8.0 Hz, 2H), 7.36 (t, J = 7.2 Hz, 1H), 6.76 (t, J = 56.0 Hz, 1H), 5.24-5.15 (m, 2H), 4.98-4.80 (m, 1H), 4.58-4.42 (m, 1H), 4.33-4.23 (m, 1H), 3.64-3.58 (m, 1H), 3.52-3.47 (m, 1H), 3.18-2.85 (m, 2H), 2.70 (s, 3H), 2.33-2.18 ( m, 1H ), 1.76-1.68 (m, 1H), 1.68-1.56 (m, 1H).
EXAMPLE 1.22. (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-1.15).
Figure imgf000192_0002
[0248] To a stirred solution of (2-fluoro-4-methylphenyl)methanol (200 mg, 1.43 mmol) in DMSO (5 mL) was added CDI (252 mg, 1.56 mmol). The mixture was stirred at room temperature for one hour and N-(((3S, 4 ?)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-o]pyrazin-3-amine dihydrochloride salt (420 mg, 1.30 mmol) was added. This reaction mixture was stirred overnight at 50°C. The mixture was cooled to room temperature and diluted with ethyl acetate. The mixture was washed with water, brine, dried over Na2S04 and concentrated. The residue was purified by column chromatography over silica gel (5% MeOH in DCM) to afford the title compound as an off-white powder (56 mg, 11%). MS (ESI) calcd for C20H22F2N6O2: 416.2; found: 417.3 [M+H]. *H NM (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.31-7.26 (m, 2H), 6.99 (d, J = 7.6 Hz, 1H), 6.94 (d, J = 11.2 Hz, 1H), 5.17-5.10 (m, 2H), 4.87-4.72 (m, 1H), 4.49-4.36 (m, 1H), 4.28-4.16 (m, 1H), 3.67- 3.62 (m, 1H), 3.59-3.54 (m, 1H), 3.12-2.80 (m, 2H), 2.34 (s, 3H), 2.29-2.12 ( m, 1H), 1.72-1.54 (m, 2H).
EXAMPLE 1.22a. (3S,4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-1.15a).
Figure imgf000193_0001
CH3S03H
[0249] To a solution of (3S, 4/?)-2-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyrazin-3-ylamino) methyl)-3-fluoropiperidine-l-carboxylate (48 mg, 0.12 mmol) in DCM (2 mL) was added methanesulfonic acid in MeOH (0.12 mL, 1.0 M, 0.12 mmol). The mixture was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as an off-white powder (55 mg, 96%). MS (ESI) calcd for C20H22F2N6O2: 416.2; found: 417.3 [M+H]. *H NMR (400 MHz, CD3OD) δ 9.32 (s, 1H), 7.95 (d, J = 5.6 Hz, 1H), 7.30 (t, J = 8.0 Hz, 1H), 7.23 (d, J = 5.6 Hz, 1H), 6.99 (d, J = 7.6 Hz, 1H), 6.94 (d, J = 11.2 Hz, 1H), 5.17-5.10 (m, 2H), 4.86-4.73 (m, 1H), 4.53-4.39 (m, 1H), 4.30-4.18 (m, 1H), 3.79-3.74 (m, 1H), 3.63-3.57 (m, 1H), 3.17-2.83 (m, 2H), 2.71 (s, 3H), 2.35 (s, 3H), 2.34-2.18 (m, 1H ), 1.79-1.58 (m, 2H).
EXAMPLE 1.23. (3S,4/?)-4-(trifluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate (El-1.12).
Figure imgf000193_0002
[0250] To a stirred solution of (4-(trifluoromethoxy)phenyl)methanol (250 mg, 1.30 mmol) in DMSO (5 mL) was added CDI (195 mg , 1.20 mmol). After stirring for lh at rt, N-(((3S,4R)-3-fluoropiperidin-4- yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride salt (286 mg, 1.00 mmol) was added. The reaction mixture was warmed to 50 °C and stirred overnight. The reaction mixture was diluted with ethyl acetate, washed with water and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated. The concentrate was purified by column chromatography over silica gel (DCM / MeOH = 40:1) to afford the title compound as a white powder (190 mg, 40%). MS (ESI) calcd for C20H20F4N6O3: 468.2; found: 469.3[M+H]. H NM R (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.47 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 4.8 Hz, 1H), 7.27 (d, J = 8.0 Hz, 2H), 5.20- 5.10 (m, 2H), 4.93-4.73 (m, 1H), 4.53-4.40 (m, 1H), 4.30-4.20 (m, 1H), 3.69-3.53 (m, 2H), 3.15-2.80 (m, 2H), 2.31-2.13 (m, 1H), 1.73-1.55 (m, 2H).
EXAMPLE 1.23a. (3S,4/?)-4-(trifluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate methanesulfonate (El-1.12a).
Figure imgf000194_0001
[0251] To a stirred solution of (3S,4R)-4-(trifluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]-pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (180 mg, 0.39 mmol) in MeOH (2.0 mL) was added CH3S03H in MeOH (0.5M, 0.78 mL, 0.78 mmol) at rt. After stirring for 30 min, the mixture was concentrated to afford the title compound as an off-white powder (217 mg, 100%). MS (ESI) calcd for C20H20F4N6O3: 468.2; found: 469.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.33 (s, 1H), 7.97 (d, J = 4.8 Hz, 1H), 7.47 (d, J = 8.0 Hz, 2H), 7.27 (d, J = 8.0 Hz, 2H), 7.25 (d, J = 4.8 Hz, 1H), 5.20-5.10 (m, 2H), 4.85-4.75 (m, 1H), 4.56-4.44 (m, 1H), 4.34-4.24 (m, 1H), 3.82-3.57 (m, 2H), 3.22-2.85 (m, 2H), 2.71 (s, 3H), 2.37-2.22 (m, 1H), 1.81-1.73 (m, 1H), 1.72-1.60 (m, 1H).
EXAMPLE 1.24. (3S,4/?)-4-(difluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]-pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate (El-1.13).
Figure imgf000195_0001
[0252] A solution of (4-(difluoromethoxy)phenyl)methanol (155 mg, 0.88 mmol) and CDI (155 mg, 0.95 mmol) in DMSO (3.0 mL) was stirred at room temperature for 1 h. After the alcohol was consumed, N-(((3S,4R)-3-fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride salt (220 mg, 0.68 mmol) was added. The resulting mixture was heated to 80 °C under N2 atmosphere, and stirred overnight. The mixture was diluted with EtOAc, washed with water, brine, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (DCM/EtOAc = 1/3) to afford the title compound as gray powder (120 mg, 39%). MS (ESI) calcd for C20H21F3N6O3: 450.2; found: 451.3 [M+H]. *H NM R (400 MHz, CDCI3) δ 8.72 (s, 1H), 7.41 (d, J = 4.8 Hz, 1H), 7.36 (d, J = 8.0 Hz, 2H), 7.34 (d, J = 4.8 Hz, 1H), 7.11 (d, J = 8.0 Hz, 2H), 6.75-6.67 (m, 1H), 6.51 (t, J = 73.6 Hz, 1H), 5.17-5.07 (m, 2H), 4.91-4.69 (m, 1H), 4.62-4.41 (m, 1H), 4.39-4.20 (m, 1H), 3.73-3.65 (m, 2H), 3.01-2.71 (m, 2H), 2.26-2.08 (m, 1H), 1.76-1.65 (m, 2H).
EXAMPLE 1.24a. (3S,4/?)-4-(difluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate methanesulfonate (El-1.13a).
Figure imgf000195_0002
[0253] To a stirred solution of (3S,4R)-4-(difluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]-pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (114 mg, 0.25 mmol) in DCM (2 mL) was added methylsulfonic acid in methanol (0.50 mL, 0.5M, 0.25 mmol) at room temperature. After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (125 mg, 100%). MS (ESI) calcd for C20H21F3N6O3: 450.2; found: 451.3 [M+H]. *H NM R (400 M Hz, CD3OD) δ 9.33 (s, 1H), 7.97 (d, J = 4.8 Hz, 1H), 7.41 (d, J = 8.0 Hz, 2H), 7.24 (d, J = 4.8 Hz, 1H), 7.13 (d, J = 8.0 Hz, 2H), 6.82 (t, J = 73.6 Hz, 1H), 5.16-5.07 (m, 2H), 4.95-4.57 (m, 1H), 4.54-4.44 (m, 1H), 4.31-4.24 (m, 1H), 3.80-3.75 (m, 1H), 3.63-3.58 (m, 1H), 3.20-2.85 (m, 1H), 2.71 (s, 3H), 2.38-2.19 (m, 1H), 1.80- 1.71 (m, 1H), 1.71-1.59 (m, 1H).
EXAMPLE 1.25. (3S,4 ?)-4-(l,l-difluoroethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate (El-1.9).
Figure imgf000196_0001
Step 1: methyl 4-(l,l-difluoroethyl)benzoate
Figure imgf000196_0002
[0254] To a solution of methyl 4-acetylbenzoate (5.0 g, 28 mmol) and DAST (11 mL, 84 mmol) in chloroform (15 mL) in a 50 mL pressure reaction tube was added EtOH (0.15 mL, 3.0 mmol). The resulting mixture was heated at 80°C overnight. After cooling to room temperature, the reaction mixture was poured into a saturated solution of NaHCO3 (150 mL), and then extracted with DCM. The organic layer was dried over sodium sulfate, filtered, and concentrated. The concentrate was purified by column chromatography over silica gel (hexane / ethyl acetate = 15:1) to afford the title compound as a colorless oil (5.4 g, 96%). *H NM (400 MHz, CDCI3) δ 8.10 (d, J = 8.4 Hz, 2H), 7.58 (d, J = 8.4 Hz, 2H), 3.94 (s, 3H), 1.93 (t, J = 18.0 Hz, 3H).
Step 2: (4-(l,l-difluoroethyl)phenyl)methanol
Figure imgf000196_0003
[0255] To a suspension of LiAIH4 (626 mg, 16.5 mmol) in dry THF (30 mL) was added methyl 4-(l,l- difluoroethyl)benzoate (2.0 g, 10 mmol) in dry THF (20 mL) dropwise at 0 °C under N2 atmosphere. The mixture was warmed to 50 °C, and stirred for 3 hours. After the ester was consumed, the reaction mixture was quenched with 3N HCI under ice-water bath cooling, and extracted with ethyl acetate. The ethyl acetate layers were dried over sodium sulfate, filtered, and concentrated. The concentrate was purified by column chromatography over silica gel (20% EtOAc-hexane) to afford the title compound as a colorless oil (1.4 g, 83%). *H NM (400 MHz, CDCI3) δ 7.51 (d, J = 8.0 Hz, 2H), 7.42 (d, J = 8.0 Hz, 2H), 4.74 (d, J = 6.0 Hz, 2H), 1.92 (t, J = 18.0 Hz, 3H), 1.75 (t, J = 6.0 Hz, 1H).
Step 3: (3S,4 ?)-4-(l,l-difluoroethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate
Figure imgf000197_0001
[0256] To a stirred solution of (4-(l,l-difluoroethyl)phenyl)methanol (300 mg, 1.74 mmol) in DMSO (4 mL) was added CDI (261 mg, 1.61 mmol). After stirred for lh at rt, N-(((3S,4R)-3-fluoropiperidin-4- yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine dihydrochloride salt (384 mg, 1.34 mmol) was added and the reaction mixture was warmed to 50 °C and stirred overnight. The reaction mixture was diluted with ethyl acetate, washed with water and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated. The concentrate was purified by column chromatography over silica gel (DCM / MeOH = 25:1) to afford the title compound as a white powder (116 mg, 15%). MS (ESI) calcd for C21H23F3N602: 448.2; found: 449.1[M+H]. *H NMR (400 MHz, CDCI3) δ 8.72 (s, 1H), 7.50 (d, J = 8.0 Hz, 2H), 7.41 (d, J = 4.8 Hz, 1H), 7.40 (d, J = 8.0 Hz, 2H), 7.34 (d, J = 4.8 Hz, 1H), 6.73-6.65 (m, 1H), 5.21-5.13 (m, 2H), 4.92-4.69 (m, 1H), 4.65-4.43 (m, 1H), 4.42-4.20 (m, 1H), 3.70 (t, J = 6.8 Hz, 2H), 3.10-2.78 (m, 2H), 2.27-2.09 (m, 1H), 1.91 (t, J = 18.0 Hz, 3H), 1.78-1.70 (m, 2H).
EXAMPLE 1.25a. (3S,4 ?)-4-(l,l-difluoroethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)- 3-fluoropiperidine-l-carboxylate methanesulfonate (El-1.9a).
Figure imgf000198_0001
[0257] To a solution of (3S,4 )-4-(l,l-difluoroethyl)benzyl 4-(([l,2,4]triazolo[4,3-a]-pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (110 mg, 0.25 mmol) in MeOH (2.0 mL) was added methanesulfonic acid in MeOH (1M, 0.25 mL, 0.25mmol) at rt. After stirring for 30 min, the mixture was concentrated to afford the title compound as an off-white powder (130 mg, 97%). MS (ESI) calcd for C21H23F3N602: 448.2; found: 449.4[M+H]. *H NM R (400 MHz, CD3OD) δ 9.33 (s, 1H), 7.97 (d, J = 5.6 Hz, 1H), 7.52 (d, J = 8.0 Hz, 2H), 7.45 (d, J = 8.0 Hz, 2H), 7.25 (d, J = 5.6 Hz, 1H), 5.25- 5.11 (m, 2H), 4.85-4.74 (m, 1H), 4.54-4.45 (m, 1H), 4.34-4.24 (m, 1H), 3.82-3.74 (m, 1H), 3.65-3.58 (m, 1H), 3.23-2.85 (m, 2H), 2.71 (s, 3H), 2.40-2.20 (m, 1H), 1.91 (t, J = 18.0 Hz, 3H), 1.81-1.60 (m, 2H).
EXAMPLE 1.26. (3S,4 ?)-4-methylbenzyl 3-fluoro-4-((3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]-pyrazin-8- ylamino)methyl)piperidine-l-carboxylate (El-1.27).
Figure imgf000198_0002
Step 1: 2-chloro-3-hydrazinylpyrazi
Figure imgf000198_0003
[0258] 2,3-dichloropyrazine (10.0 g, 67.6 mmol) was dissolved in ethanol (95%, 120 ml) and 85% hydrazine hydrate (25.6 mL, 338 mmol) was added dropwise with stirring. After stirring for 4 hours, the mixture was cooled to ice-water bath temperature. The mixture was filtered and the filter pad washed with cold ethanol (95%), collected and dried to give the title compound as a light yellow powder (6.5 g, 67%). Step 2: 3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-ol
Figure imgf000199_0001
[0259] A mixture of 2-chloro-3-hydrazinylpyrazine (2.0 g, 13.9 mmol), trifluoroacetic acid (3.1 m L, 42 mmol), and polyphosphoric acid (15 m L) was heated to 140°C with stirring overnight. The solution was poured over ice and neutralized by the addition of ammonium hydroxide. The aqueous solution was extracted 3 times with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate and concentrated. The residue was purified by column chromatography over silica gel (DCM/ MeOH = 40/1) to afford the title compound as a yellow powder (1.9 g, 68%). MS (ESI) calcd for C6H3F3N40: 204.0 ; found: 205.2 [M+H].
Step 3: 8-chloro-3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]pyrazine
Figure imgf000199_0002
[0260] To a solution of 3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-ol (500 mg, 2.5 mmol) in phosphorus oxychloride (5 mL) was added two drops of DM F, and the reaction mixture was heated to 100°C. After stirring for 4 hours at 100°C, the mixture was cooled down to rt and poured onto ice. The mixture obtained was neutralized by the addition of sodium bicarbonate. The aqueous solution was extracted with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate and concentrated. The residue was purified by column chromatography over silica gel (DCM/MeOH = 40/1) to afford the title compound as a yellow powder (504 mg, 93%). MS (ESI) calcd for C6H2CI F3N4: 222.0 ; found: 223.1 [M+H]. *H N M (400 M Hz, CDCI3) δ 8.14 (d, J = 4.8 Hz, 1H), 7.94 (d, J = 4.8 Hz, 1H).
Step 4: (3S,4R)-4-methylbenzyl 3-fluoro-4-((3-(trifluoromethyl)-[l,2,4]-triazolo[4,3-a]pyrazin-8- ylamino)methyl)piperidine-l-carboxylate
Figure imgf000200_0001
[0261] A mixture of (3S,4R)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (150 mg, 0.53 mmol), 8-chloro-3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]pyrazine (134 mg, 0.59 mmol) and DIPEA (0.18 mL, 1.1 mmol ) in butyl alcohol (3 mL) was heated to 120°C. After stirring overnight at 120°C, the orange solution was concentrated. The concentrate was purified by column chromatography over silica gel (hexane/ ethyl acetate = 1:3) to afford the title compound as a white powder (150 mg, 68%). MS (ESI) calcd for C21H22F4N602:446.2 ; found: 467.0 [M+H]. *H NMR (400 MHz, CDCI3) δ 7.50 (d, J = 4.8 Hz, 1H), 7.48 (d, J = 4.8 Hz, 1H), 7.25 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 6.74 (br s, 1H), 5.10 (s, 2H), 4.87-4.42 (m, 2H), 4.42-4.18 (m, 1H), 3.73 (s, 2H), 3.02-2.70 (m, 2H), 2.35 (s, 3H), 2.26-2.07 (m, 1H), 1.76-1.67 (m, 2H).
EXAMPLE 1.26a. (3S,4 ?)-4-methylbenzyl 3-fluoro-4-((3-(trifluoromethyl)-[l,2,4]triazolo[4,3-a]-pyrazin-8- ylamino)methyl)piperidine-l-carboxylate methanesulfonate (El-1.27).
Figure imgf000200_0002
[0262] To a stirred solution of (3S,4R)-4-methylbenzyl 3-fluoro-4-((3-(trifluoromethyl)-[l,2,4]triazolo- [4,3-a]pyrazin-8-ylamino)methyl)piperidine-l-carboxylate (150 mg, 0.32 mmol) in DCM/MeOH (1 mL / 1 mL) was added methanesulfonic acid in methanol (0.32 mL, 1.0M, 0.32 mmol). The mixture was stirred for 15min, and concentrated to afford the title compound as a white powder (167 mg, 93%). MS (ESI) calcd for C21H22F4N602:446.2 ; found: 467.1 [M+H]. *H NM R (400 MHz, CD3OD) δ 7.94 (d, J = 5.6 Hz, 1H), 7.42 (d, J = 5.6 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.84- 4.74 (m, 1H), 4.52-4.45 (m, 1H), 4.31-4.24 (m, 1H), 3.82-3.76 (m, 1H), 3.66-3.60 (m, 1H), 3.22-2.82 (m, 2H), 2.70 (s, 3H), 2.33 (s, 3H), 2.31-2.19 (m, 1H), 1.80-1.60 (m, 2H). EXAMPLE 1.27. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-1.2).
Figure imgf000201_0001
[0263] A mixture of 8-chloro-[l,2,4]triazolo[4,3-a]pyrazine (100 mg, 0.65 mmol), (3S,4R)-4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (246 mg, 0.78 mmol) and DIPEA (0.56 mL, 3.24 mmol) in n-BuOH (3 mL) was heated to 120°C under N2 atmosphere. After stirring overnight at 120°C, the mixture was cooled down to room temperature and concentrated under vacuum. The concentrate was partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: 100% ethyl acetate) to afford the title compound as a brown powder (210 mg, 62%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, C/6-DMSO) δ 9.20 (s, 1H), 8.33-8.25 (m, 1H), 7.75 (d, J = 4.8 Hz, 1H), 7.28 (d, J = 4.8 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.02 (s, 2H), 4.91-4.70 (m, 1H), 4.33-4.18 (m, 1H), 4.11-4.00 (m, 1H), 3.57-3.51 (m, 1H), 3.43-3.36 (m, 1H), 3.13-2.97 (m, 1H), 2.93-2.71 (m, 1H), 2.29 (s, 3H), 2.26-2.09 (m, 1H), 1.61-1.52 (m, 1H), 1.46-1.34 (m, 1H).
EXAMPLE 1.27a. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonic acid (El-1.2a).
Figure imgf000201_0002
CH3SO3H
[0264] To a solution of (3S,4R)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate (210 mg, 0.53 mmol) in methanol (1.5 mL) was added methanesulfonic acid in methanol (5.3 mL, 0.1 M, 0.53 mmol) at room temperature. After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (260 mg, 100%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NM (400 MHz, CD3OD) δ 9.35 (s, 1H), 7.99 (d, J = 5.6 Hz, 1H), 7.27 (d, J = 5.6 Hz, 1H), 7.26 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.10 (s, 2H), 4.90-4.76 (m, 1H), 4.56-4.45 (m, 1H), 4.33-4.24 (m, 1H), 3.82-3.77 (m, 1H), 3.65- 3.60 (m, 1H), 3.21-3.03 (m,lH), 3.03-2.85 (m, 1H), 2.73 (s, 3H), 2.35 (s, 3H), 2.32-2.20 (m, 1H), 1.72- 1.60 (m, 1H).
EXAMPLE 1.28. (3 ?,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (E2-1.2).
Figure imgf000202_0001
[0265] A mixture of 8-chloro-[l,2,4]triazolo[4,3-a]pyrazine (120 mg, 0.78 mmol), (3R,4S)-4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (297 mg, 0.94 mmol) and DIPEA (0.65 mL, 3.9 mmol) in n-BuOH (4 mL) was heated to 120°C under N2 atmosphere. After stirring overnight at 120°C, the mixture was cooled down to room temperature and concentrated under vacuum. The concentrate was partitioned into EtOAc and water. The organic phase was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: 100% ethyl acetate) to afford the title compound as a brown powder (187 mg, 78%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.09 (s, 1H), 7.69 (d, J = 4.8 Hz, 1H), 7.30 (d, J = 4.8 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.85-4.71 (m, 1H), 4.50-4.40 (m, 1H), 4.28-4.20 (m, 1H), 3.68-3.63 (m, 1H), 3.60-3.55 (m, 1H), 3.11-3.00 (m, 1H), 2.95-2.80 (m, 1H), 2.33 (s, 3H), 2.30-2.11 (m, 1H), 1.71-1.57 (m, 2H).
EXAMPLE 1.28a. (3 ?,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonic acid (E2-1.2a).
Figure imgf000203_0001
CH3SO3H
[0266] To a solution of (3R,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate (187 mg, 0.47 mmol) in methanol (1 mL) was added the 0.1M methanesulfonic acid in methanol (4.7 mL, 0.47 mmol) at room temperature. After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (232 mg, 100%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.33 (s, 1H), 7.97 (d, J = 5.6 Hz, 1H), 7.25 (d, J = 5.6 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.85-4.74 (m, 1H), 4.54-4.43 (m, 1H), 4.32-4.23 (m, 1H), 3.81-3.75 (m, 1H), 3.64- 3.58 (m, 1H), 3.18-3.03 (m, 1H), 3.01-2.84 (m, 1H), 2.72 (s, 3H), 2.33 (s, 3H), 2.29-2.19 (m, 1H), 1.81- 1.57 (m, 2H).
EXAMPLE 1.29. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-2.2).
Figure imgf000203_0002
[0267] A mixture of 5-bromo-[l,2,4]triazolo[4,3-a]pyrazine (280 mg, 1.40 mmol), (3S,4R)- 4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (532 mg, 1.68 mmol), Brettphos precatalyst (30 mg), Brettphos (30 mg), and Cs2C03 (2.28 g, 7.0 mmol) in t-BuOH (7 mL) was heated to 120°C in the sealed tube under N2 atmosphere. After stirring overnight at 100°C, the mixture was cooled down to room temperature and concentrated under vacuum. The concentrate was partitioned into DCM and water. The aqueous phase was extracted with DCM. The combined organic phases were washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: 100% ethyl acetate) to afford the title compound as a brown powder (106 mg, 19%). MS (ESI) calcd for C2oH23FN602: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, CDCI3) δ 8.72 (s, 1H), 7.45-7.30 (m, 4H), 7.26-7.20 (m, 2H), 7.20-7.12 (m, 2H), 6.68-6.52 (m, 1H), 5.10 (br s, 2H), 4.95-4.65 (m, 1H), 4.63-4.16 (m, 2H), 3.77-3.62 (m, 2H), 3.02-2.67 (m, 2H), 2.35 (s, 3H), 2.25-1.97 (m, 1H), 1.65-1.46 (m, 2H).
EXAMPLE 1.29a. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonic acid (El-2.2a).
Figure imgf000204_0001
CH3S03H
[0268] To a solution of (3S,4R)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (77 mg, 0.19 mmol) in methanol (1 mL) was added methanesulfonic acid in methanol (1.95 mL, 0.1 M, 0.195 mmol) at room temperature. After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (95 mg, 100%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NM R (400 MHz, CD3OD) δ 9.33 (s, 1H), 7.97 (d, J = 5.6 Hz, 1H), 7.27-7.21 (m, 3H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.86-4.74 (m, 1H), 4.54- 4.43 (m, 1H), 4.31-4.24 (m, 1H), 3.81-3.75 (m, 1H), 3.64-3.58 (m, 1H), 3.21-2.82 (m, 3H), 2.71 (s, 3H), 2.33 (s, 3H), 2.30-2.18 (m, 1H), 1.71-1.60 (m, 2H).
EXAMPLE 1.30. (3 ?,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (E2-2.2).
Figure imgf000204_0002
[0269] A mixture of 5-bromo-[l,2,4]triazolo[4,3-a]pyrazine (160 mg, 0.80 mmol), (3R,4S)-4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (306 mg, 0.96 mmol), Brettphos precatalyst (20 mg), Brettphos (20 mg), and Cs2C03 (789 mg, 2.4 mmol) in t-BuOH (6 mL) was heated to 100°C in the sealed tube under N2 atmosphere. After stirring overnight at 100°C, the mixture was cooled down to room temperature and concentrated under vacuum. The concentrate was partitioned into DCM and water. The aqueous phase was extracted with DCM. The combined organic phases were washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (eluent: 100% ethyl acetate) to afford the title compound as a brown powder (92 mg, 28%). MS (ESI) calcd for C2oH23FN602: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, CDCI3) δ 8.72 (s, 1H), 7.41 (d, J = 4.4 Hz, 1H), 7.34 (d, J = 4.4 Hz, 1H), 7.25 (d, J = 7.2 Hz, 2H), 7.17 (d, J = 7.2 Hz, 2H), 6.58 (br s, 1H), 5.09 (br s, 2H), 4.90-4.69 (m, 1H), 4.65-4.15 (m, 2H), 3.75-3.60 (m, 2H), 3.02-2.70 (m, 2H), 2.35 (s, 3H), 2.24-2.08 (m, 1H), 1.75- 1.65 (m, 2H).
EXAMPLE 1.30a. (3 ?,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (E2-2.2a).
Figure imgf000205_0001
CH3S03H
[0270] To a solution of (3R,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (92 mg, 0.23 mmol) in methanol (2 mL) was added the 0.1M methanesulfonic acid in methanol (2.3 mL, 0.23 mmol) at room temperature. After stirring for 30 min, the solution was concentrated to afford the title compound as an off-white powder (111 mg, 100%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.3[M+H]. *H NMR (400 MHz, CD3OD) δ 9.34 (s, 1H), 7.97 (d, J = 5.6 Hz, 1H), 7.24 (d, J = 5.6 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.88-4.74 (m, 1H), 4.54-4.43 (m, 1H), 4.32-4.23 (m, 1H), 3.80-3.75 (m, 1H), 3.63-3.58 (m, 1H), 3.21-3.03 (m, 1H), 3.00-2.82 (m, 1H), 2.72 (s, 3H), 2.33 (s, 3H), 2.28-2.21 (m, 1H), 1.80-1.57 (m, 2H).
EXAMPLE 1.31. c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (C-5.1).
Step 1: c/s-4-methylbenzyl 3-fluoro-4-((l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazolo[3,4-d]pyrim- idin-4-ylamino)methyl)piperidine-l-carboxylate
Figure imgf000206_0002
[0271] A stirred mixture of cis-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate (200 mg, 0.71 mmol), 4-chloro-l-(tetrahydro-2H-pyran-2-yl)-lH-pyrazolo-[3,4-d]pyrimidine (204 mg, 0.86 mmol) and DIPEA (185 mg, 1.43 mmol) in n-butyl alcohol (4 mL) was heated to 130°C. After stirring overnight at 130°C, the reaction solution was concentrated and treated with EtOAc. The organic layers were washed with water, brine, dried and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 25/1) to afford the title compound as a pale- yellow solid (104 mg, 30%). MS (ESI) calcd for C25H3iFN603:482.2; found: 483.5 [M+H]. *H NM (400 MHz, CDCI3) δ 8.40 (brs, 1H), 7.96 (s, 1H), 7.25 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.96 (d, J = 9.2 Hz, 1H), 5.16-5.03 (m, 2H), 4.87-4.23 (m, 3H), 4.13-4.09 (m, 1H), 3.83-3.75 (m, 1H), 3.68-3.66 (m, 2H), 2.99-2.77 (m, 2H), 2.62-2.50 (m, 1H), 2.35 (s, 3H), 2.14-2.08 (m, 2H), 1.97-1.90 (m, 2H), 1.80- 1.73 (m, 2H), 1.67-1.58 (m, 3H).
Step 2: c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate
Figure imgf000207_0001
[0272] To a stirred solution of (c/s-4-methylbenzyl 3-fluoro-4-((l-(tetrahydro-2H-pyran-2-yl)-lH- pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)piperidine-l-carboxylat (104 mg, 0.22 mmol) in MeOH (3 ml) was added HCI/Et20 (2M, 2 ml) at rt. After stirring for 4 hours, the mixture was concentrated and extracted with EtOAc. The organic phase was washed with saturated sodium bicarbonate, brine, dried over anhydrous Na2S04 and concentrated under reduced pressure to afford the title compound as an off-white powder (85 mg, 100%). MS (ESI) calcd for C2oH23FN602:398.2; found: 399.4 [M+H]. *H NM (400 MHz, d6-DMSO) δ 13.3 (brs, IH), 8.41-8.39 (m, IH), 8.22 (s, IH), 8.13 (s, IH), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.02 (s, 2H), 4.90-4.75 (m, IH), 4.32-4.21 (m, IH), 4.12-4.02 (m, IH), 3.53- 3.33 (m, 2H), 3.04 -2.76 (m, 2H), 2.29 (s, 3H), 2.18-1.96 (m, IH), 1.61-1.52 (m, IH), 1.46-1.34 (m, IH).
EXAMPLE 1.31a. c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (C-5.1a).
Figure imgf000207_0002
[0273] To a stirred solution of c/s-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-4-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (80 mg, 0.20 mmol) in MeOH (10 mL) was added 1.0 M CH3S03H in methanol (0.2 mL, 0.20 mmol) at rt. After stirring for lh, the mixture was concentrated to afford the title compound as a pale-yellow powder (108 mg, 100%). MS (ESI) calcd for C2oH23FN602:398.2; found: 399.4 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 13.30 (brs, IH), 8.43-8.37 (m, IH), 8.22 (s, IH), 8.14 (s, IH), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.02 (s, 2H), 4.91-4.73 (m, IH), 4.32-4.20 (m, IH), 4.15-4.01 (m, IH), 3.55-3.38 (m, 2H), 3.04-2.77 (m, 2H), 2.31 (s, 3H), 2.29 (s, 3H), 2.18- 1.95 (m, IH), 1.64-1.54 (m, IH), 1.46 -1.34 (m, IH). EXAMPLE 1.32. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyridin-2-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-25.2).
Figure imgf000208_0001
[0274] To a stirred suspension of (3S,4 ?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (870 mg, 2.75 mmol) in f-butyl alcohol (20 mL) was added 2-bromo- [l,2,4]triazolo[l,5-o]pyridine (500 mg, 2.54 mmol), Brettphos precatalyst (50 mg), Brettphos (50 mg) and Cs2C03 (2.45 g, 7.52 mmol), then the mixture was heated to 100 °C under nitrogen. After stirring overnight, the mixture was cooled down to room temperature and diluted with DCM and filtered through celite. The filtrate was washed with water, dried over Na2S04 and concentrated in vacuo. The residue was purified by column chromatography over silica gel (50% hexanes in EtOAc) to afford the title compound as a white powder (355 mg, 36%). MS (ESI) calcd for C21H24FN5O2: 397.2; found: 398.4 [M+H]. *H NM (400 MHz, CD3OD) δ 8.42 (d, J = 6.8 Hz, 1H), 7.52-7.48 (m, 1H), 7.36 (d, J = 8.8 Hz, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.95-6.92 (m, 1H), 5.08 (s, 2H), 4.87-4.72 (m, 1H), 4.50-4.40 (m, 1H), 4.27-4.20 (m, 1H), 3.44-3.39 (m, 1H), 3.33-3.28 (m, 1H), 3.13-2.79 (m, 2H), 2.33 (s, 3H), 2.19-2.03 ( m, 1H ), 1.70-1.50 (m, 2H).
EXAMPLE 1.32a. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyridin-2-ylamino)methyl)- 3-fluoro- piperidine-l-carboxylate methanesulfonate (El-25.2a).
Figure imgf000208_0002
[0275] To a solution of (3S, 4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[l,5-a]pyridin-2-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (349 mg, 0.88 mmol) in DCM (8 mL) was added methane sulfonic acid in MeOH (0.88 mL, 1.0 M, 0.88 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as a white powder (421mg, 97%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.4 [M+H]. *H NM (400 MHz, CD3OD) δ 8.78 (d, J = 6.8 Hz, 1H), 8.03-7.99 (m, 1H), 7.73 (d, J = 8.8 Hz, 1H), 7.51-7.45 (m, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.86-4.72 (m, 1H), 4.51-4.42 (m, 1H), 4.29-4.21 (m, 1H), 3.54-3.48 (m, 1H), 3.43-3.37 (m, 1H), 3.15-2.81 (m, 2H), 2.71 (s, 3H), 2.33 (s, 3H), 2.25-2.08 ( m, 1H ), 1.71-1.52 (m, 2H).
EXAMPLE 1.33. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-6.2).
Figure imgf000209_0001
Step 1: 2-hydrazinylpyridine
Figure imgf000209_0002
[0276] 2-Chloropyridine (3.0 mL, 32 mmol) was mixed with hydrazine hydrate (15 mL), and the mixture was heated under reflux. After stirring overnight, the reaction was cooled to room temperature. The solvent was evaporated to afford the title compound as a yellow oil (2.1 g, 61%). MS (ESI) calcd for C5H7N3: 109.1; found: 110.2 [M+H]. *H NMR (400 MHz, CDCI3) δ 8.14 (d, J = 4.4 Hz, 1H), 7.52-7.47 (m, 1H), 6.71-6.67 (m, 2H), 5.77 (br s, 1H), 3.81 ( br s, 2H ).
Step 2: (3S,4/?)-4-methylbenzyl 3-fluoro-4-((2-(pyridin-2-yl)hydrazinecarboxamido)methyl)- piperidine-l-carboxylate
Figure imgf000209_0003
[0277] (3S,4 ?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate (1.0 g, 3.6 mmol) in dichloromethane (4 mL) was added to a solution of triphosgene (400 mg, 1.35 mmol) in dichloromethane (7 mL) at 0 °C under nitrogen. Triethylamine (1.1 m L, 7.7 mmol) in dichloromethane (4 m L) was then added dropwise and the mixture was stirred at room temperature. After stirring for 2 hours, the mixture was cooled to 0 °C, 2-hydrazinylpyridine (414 mg, 3.40 mmol) in dichloromethane (7 m L) was added and the mixture was stirred overnight at room temperature. The mixture was diluted with dichloromethane, and washed with saturated NaHC03, brine, dried over Na2S04 and concentrated under reduce pressure. The residue was purified by column chromatography over silica gel (4% MeOH-DCM) to afford the title compound as an off-white powder (860 mg, 59 %). MS (ESI) calcd for C21H26FN503: 415.2; found: 416.6 [M+H]. *H N M (400 M Hz, CD3OD) δ 8.06 (d, J = 4.8 Hz, 1H), 7.64-7.60 (m, 1H), 7.22 (d, J = 7.6 Hz, 2H), 7.16 (d, J = 7.6 Hz, 2H), 6.83-6.80 (m, 1H), 6.77 (d, J = 8.4 Hz, 1H), 5.07 (s, 2H), 4.76-4.56 (m, 1H), 4.44-4.34 (m, 1H), 4.23-4.15 (m, 1H), 3.29-3.22 (m, 1H), 3.18-3.13 (m, 1H), 3.07-2.74 (m, 2H), 2.33 (s, 3H), 1.98- 1.83 ( m, 1H ), 1.57-1.44 (m, 2H).
Step 3: (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate
Figure imgf000210_0001
[0278] Hexachloroethane (1.92 g, 8.19 mmol) was added portionwise to a stirred solution of (3S, 4 ?)-4- methylbenzyl 3-fluoro-4-((2-(pyridin-2-yl)hydrazinecarboxamido)methyl)piperidine-l-carboxylate (850 mg, 2.05 mmol), triphenylphosphine (2.15 g, 8.19 mmol) and triethylamine (2.32 ml, 16.4 mmol) in dry TH F (25 mL) at room temperature. After stirring overnight the resulting suspension was filtered through celite, and the filtrate was concentrated in vacuo. The residue was dissolved in ethyl acetate, and the solution was washed with water, brine, dried over Na2S04 and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel (5% MeOH-DCM ) to afford the title compound as an off-white powder (351 mg, 43%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.2 [M+H]. *H NM R (400 M Hz, CD3OD) δ 8.02 (d, J = 6.8 Hz, 1H), 7.43 (d, J = 9.6 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.22 (d, J = 9.6 Hz, 1H), 7.16 (d, J = 8.0 Hz, 2H), 6.81 (t, J = 6.8 Hz, 1H), 5.08 (s, 2H), 4.95-4.76 (m, 1H), 4.50-4.41 (m, 1H), 4.29-4.21 (m, 1H), 3.58-3.52 (m, 1H), 3.47-3.42 (m, 1H), 3.11-2.82 (m, 2H), 2.33 (s, 3H), 2.28-2.11 ( m, 1H ), 1.75-1.55 (m, 2H).
EXAMPLE 1.33a. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-6.2a).
Figure imgf000211_0001
[0279] To a solution of (3S, 4 ?)-4-methylbenzyl-4-(([l,2,4]triazolo[4,3-o]pyridin-3-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (346 mg, 0.86 mmol) in MeOH (7 mL) was added 1 M methylsulfonic acid in MeOH (0.86 mL, 0.86 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as an off-white powder (410 mg, 97%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.2 [M+H]. *H NMR (400 MHz, CD3OD) δ 8.46 (d, J = 7.2 Hz, 1H), 7.90 (dd, J = 8.0 and 7.2 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H), 7.34 (t, J = 7.2 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.97-4.76 (m, 1H), 4.51-4.42 (m, 1H), 4.29-4.23 (m, 1H), 3.63-3.58 (m, 1H), 3.51-3.46 (m, 1H), 3.13-2.81 (m, 2H), 2.70 (s, 3H), 2.33 (s, 3H), 2.31-2.16 ( m, 1H ), 1.75-1.54 (m, 2H).
EXAMPLE 1.34. (3S,4 ?)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyridin-5-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-3.2).
Figure imgf000211_0002
[0280] A mixture of 5-chloro-[l,2,4]triazolo[4,3-a]pyridine (93 mg, 0.61 mmol), (3S,4R)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (230 mg, 0.72 mmol), Brettphos precatalyst (10 mg), Brettphos (10 mg) and Cs2C03 (980 mg, 3.0 mmol) in t-BuOH (2 mL) was heated to 100°C in the sealed tube. After stirring overnight at 100°C, the mixture was concentrated. The concentrate was diluted with DCM and filtered. The filter mass was washed with DCM. The filtrate was concentrated and purified by column chromatography over silica gel (DCM/MeOH = 30/1) to afford the title compound as a pale yellow powder (85 mg, 35%). MS (ESI) calcd for C21H24FN5O2: 397.2; found: 398.3[M+H]. *H NM R (400 MHz, CDCI3) δ 9.43 (brs, 1H), 7.30-7.24 (m, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.15 (s, 1H), 7.14 (d, J = 8.0 Hz, 2H), 5.85 (d, J=7.2 Hz, 1H), 5.15-5.00 (m, 2H), 4.98-4.73 (m, 1H), 4.58-4.38 (m, 1H), 4.35-4.16 (m, 1H), 3.53-3.42 (m, 1H), 3.35-3.25 (m, 1H), 3.02-2.68 (m, 2H), 2.33 (s, 3H), 2.30-2.13 (m, 1H), 1.71-1.58 (m, 2H).
EXAMPLE 1.35. (3 ?,4S)-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyridin-5-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (E2-3.2).
Figure imgf000212_0001
[0281] A mixture of 5-chloro-[l,2,4]triazolo[4,3-a]pyridine (124 mg, 0.80 mmol), (3R,4S)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (304 mg, 0.96 mmol), Brettphos precatalyst (20 mg), Brettphos (20 mg) and Cs2C03 (815 mg, 2.5 mmol) in t-BuOH (2 mL) was heated to 100°C in a sealed tube. After stirring overnight at 100°C, the mixture was concentrated. The concentrate was diluted with DCM and filtered. The filter mass was washed with DCM. The filtrate was concentrated and purified by column chromatography over silica gel (DCM/MeOH = 30/1) to afford the title compound as a pale yellow powder (57 mg, 18%). MS (ESI) calcd for C21H24FN5O2: 397.2; found: 398.3[M+H]. *H NMR (400 MHz, CDCI3) δ 9.30 (s, 1H), 7.30-7.24 (m, 2H), 7.24 (d, J = 8.0 Hz, 2H), 7.15 (d, J = 8.0 Hz, 2H), 7.12 (d, J = 8.8 Hz, 1H), 6.85-6.70 (m, 1H), 5.90-5.82 (m, 1H), 5.15- 5.02 (m, 2H), 5.00-4.75 (m, 1H), 4.60-4.42 (m, 1H), 4.37-4.18 (m, 1H), 3.57-3.49 (m, 1H), 3.38-3.32 (m, 1H), 3.02-2.68 (m , 2H), 2.34 (s, 3H), 2.30-2.16 (m, 1H), 1.78-1.70 (s, 2H).
EXAMPLE 1.36. (3S,4/?)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate (El-1.28). M
Figure imgf000213_0001
Step 1: (3-fluoro-4-methylphenyl)methanol
Figure imgf000213_0002
[0282] To a stirred suspension of LiAIH4 (0.51 g, 12.9 mmol) in dried THF (10 mL) was added dropwise a solution of 3-fluoro-4-methylbenzoic acid (2.02 g, 12.9 mmol) in dried THF at 0 °C under N2 atmosphere. After stirring overnight at room temperature, the mixture was quenched by addition of Na2S04 10H2O. After stirring at r.t. for 30 min, the solid was removed by filtration, and the filtered mass was extracted with EtOAc. The combined organic phases were washed with brine, dried Na2S04, and concentrated in vacuo. The residue was purified by column chromatography over silica gel (hexane/EtOAc = 5/1) to afford the title compound as a colorless oil (1.21 g, 67%). Η NM (400 MHz, CDCI3) δ 7.16 (t, J = 8.0 Hz, 1H), 7.04-7.01 (m, 2H), 4.65 (s, 2H), 2.26 (d, J = 1.6 Hz, 3H).
Step 2: (3S,4/?)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
M
Figure imgf000213_0003
[0283] To a stirred solution of (3-fluoro-4-methylphenyl)methanol (127 mg, 0.91 mmol) in DMSO (3 mL) was added CDI (136 mg, 0.84 mmol) at room temperature. After stirring for 1 h, N-(((3S,4R)-3- fluoropiperidin-4-yl)methyl)-[l,2,4]triazolo[4,3-a]pyrazin-8-amine hydrochloride (300 mg, 0.7 mmol) was added, and the resulting mixture was heated to 50 °C under N2 atmosphere. After stirring overnight, the mixture was diluted with EtOAc. The organic layer was washed with water, brine, dried over Na2S04 and concentrated. The concentrate was purified by column chromatography over silica gel (DCM/MeOH = 40/1) to afford the title compound as a white powder (115 mg, 30%). MS (ESI) calcd for C20H22F2N6O2: 416.2 ; found: 417.3 [M+H]. *H NM R (400 M Hz, CD3OD) δ 9.09 (s, 1H), 7.70 (d, J = 4.8 Hz, 1H), 7.30 (d, J = 4.8 Hz, 1H), 7.21 (t, J = 8.0 Hz, 1H), 7.09-7.04 (m, 2H), 5.10 (br s, 2H), 4.87-4.75 (m, 1H), 4.51-4.41 (m, 1H), 4.29-4.20 (m, 1H), 3.69-3.53 (m, 2H), 3.16-2.83 (m, 2H), 2.27 (s, 3H), 2.26-2.14 (m, 1H), 1.68-1.55 (m, 2H).
EXAMPLE 1.36a. (3S,4/?)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8-ylamino)-methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-1.28a).
Figure imgf000214_0001
CH3S03H
[0284] To a stirred solution of (3S,4R)-3-fluoro-4-methylbenzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (105 mg, 0.30 mmol) in DCM/MeOH (1 mL /1 mL) was added methanesulfonic acid in methanol (0.30 mL, 1.0 M, 0.30 mmol). The mixture was stirred for 30 min, and concentrated to afford the title compound as a white powder (115 mg, 100%). MS (ESI) calcd for C20H22F2N6O2: 416.2 ; found: 417.3 [M+H]. *H NM R (400 M Hz, CD3OD) δ 9.31 (s, 1H), 7.95 (d, J = 5.6 Hz, 1H), 7.24 (d, J = 5.6 Hz, 1H), 7.21 (t, J = 8.0 Hz, 1H), 7.06-7.00 (m, 2H), 5.10 (br s, 2H), 4.86-4.75 (m, 1H), 4.53-4.47 (m, 1H), 4.30-4.26 (m, 1H), 3.80-3.58 (m, 2H), 3.21-2.85 (m, 2H), 2.71 (s, 3H), 2.38-2.28 (m, 1H), 2.25 (s, 3H), 1.81-1.72 (m, 1H), 1.72-1.60 (m, 1H).
EXAMPLE 1.37. (3S,4R)-4-methylbenzyl 3-fluoro-4-((furo[3,2-b]pyridin-5-ylamino)-methyl)piperidine-l- carboxylate (El-17.2).
Figure imgf000215_0001
Step 1: 6-bromo-2-iodopyridin-3-ol
Figure imgf000215_0002
[0285] A solution of 6-bromopyridin-3-ol (8.00 g, 46.0 mmol) and N-iodosuccinimide (10.34 g, 46.0 mmol) in methanol (180 mL) was heated at 45 °C for 5 hours with stirring. The mixture was allowed to cool to room temperature and the solvent was removed under reduced pressure. The resulting solid was triturated with ether and collected by filtration. The solid prooduct was further triturated with DCM and dried to afford the title product as a pale pink powder (4.26 g, 30%). MS (ESI) calcd for C5H3BrlNO: 298.8; found: 301.8 [M+H]. *H NM (400 MHz, CDCI3) δ 7.31 (d, J = 8.0 Hz, 1H), 7.10 (d, 7 = 8.0 Hz, 1H), 5.45 (s, 1H).
Step 2: 6-bromo-2-iodopyridin-3-yl acetate
Figure imgf000215_0003
[0286] To a heated acetic anhydride (33 mL) solution at 130 °C was added 6-bromo-2-iodopyridin-3-ol (2.00 g, 6.67 mmol) in one portion. After stirring for 30 min at 130 °C, the mixture was allowed to cool and the acetic anhydride solvent was removed in vacuo. The concentrate was dissolved in EtOAc, washed with saturated aqueous NaHC03, brine, dried over Na2S04, and concentrated under vacuum to afford the title compound as an off-white powder (2.16 g, 95%). MS (ESI) calcd for C7H5BrlN02: 340.9; found: 341.8 and 343.8 [M+H]. *H NMR (400 MHz, CDCI3) δ 7.45 (d, J = 8.0 Hz, 1H), 7.23 (d, J = 8.0 Hz, 1H), 2.40 (s, 3H).
Step 3: 6-bromo-2-((trimethylsilyl)ethynyl)pyridin-3-yl acetate
Figure imgf000216_0001
[0287] To a stirred solution of 6-bromo-2-iodopyridin-3-yl acetate (4.70 g, 13.93 mmol) in TEA/DMF (65 mL / 20 mL) were added Pd(PPh3)2CI2 (490 mg, 0.70 mmol), Cul (265 mg, 1.39 mmol) and l-(trimethylsilyl)acetylene (2.0 mL, 13.9 mmol) sequentially under N2 atmosphere at room temperature. The resulting mixture was stirred overnight at room temperature. The mixture was concentrated under vacuum. The residue was extracted with EtOAc and the combined extracts were concentrated. The resulting concentrate was purified by column chromatography over silica gel (eluent: hexane/EtOAc = 20/1) to afford the title product as a pale brown oil (1.06 g, 24%). MS (ESI) calcd for C12H14BrN02Si: 311.0; found: 312.0 and 314.0 [M+H]. *H NM (400 MHz, CDCI3) δ 7.44 (d, J = 8.0 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 2.34 (s, 3H), 0.26 (s, 9H).
Step 4: 5-bromofuro[3,2-b]pyridine
Figure imgf000216_0002
[0288] To a stirred solution of 6-bromo-2-((trimethylsilyl)ethynyl)pyridin-3-yl acetate (1.06 g, 3.20 mmol) in methanol (15 mL) was added K2C03 (2.21 g, 16.0 mmol). The resulting mixture was warmed to 50 °C. After the starting material was consumed, the mixture was filtered, and the filtrate was concentrated. The concentrate was purified by column chromatography over silica gel (eluent: hexane/EtOAc = 10/1) to afford the title product as an off-white powder (177 mg, 28%). MS (ESI) calcd for C7H4BrNO: 197.0; found: 198.0 [M+H]. *H NMR (400 MHz, CDCI3) δ 7.86 (d, J = 2.4 Hz, 1H), 7.66 (d, J = 8.0 Hz, 1H), 7.39 (d, J = 8.0 Hz, 1H), 6.95 (d, J = 2.4 Hz, 1H).
Step 5: (3S,4R)-4-methylbenzyl 3-fluoro-4-((furo[3,2-b]pyridin-5-ylamino)-methyl)piperidine-l- carboxylate
Figure imgf000217_0001
[0289] To a stirred mixture of 5-bromofuro[3,2-b]pyridine (132 mg, 0.66 mmol) and (3S,4R)-4- methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l-carboxylate hydrochloride (254 mg, 0.80 mmol) in dioxane (3.5 mL) were added Pd2(dba)3 (131 mg, 0.13 mmol), BINAP (167 mg, 0.27 mmol) and Cs2C03 (650 mg, 1.98 mmol) under N2 atmosphere. The resulting mixture was heated to 100 °C. After stirring for 6 hours, the mixture was concentrated. The residue was purified by column chromatography over silica gel (eluent: hexane/EtOAc = 3/1) to afford the title product as a brown powder (92 mg, 35%). MS (ESI) calcd for C22H24FN303: 397.2; found: 398.2 [M+H]. *H NMR (400 M Hz, CDCI3) δ 7.67 (d, J = 2.4 Hz, 1H), 7.53 (d, J = 9.2 Hz, 1H), 7.25 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.73 (d, J = 2.4 Hz, 1H), 6.34 (d, J = 9.2 Hz, 1H), 5.15-5.05 (m, 2H), 4.90-4.20 (m, 4H), 3.50-3.36 (m, 2H), 3.00-2.72 (m, 2H), 2.35 (s, 3H), 2.16-1.98 (m, 1H), 1.66-1.64 (m, 1H).
EXAMPLE 1.37a. (3S,4R)-4-methylbenzyl 3-fluoro-4-((furo[3,2-b]pyridin-5-ylamino)-methyl)piperidine-l- carboxylate methanesulfonate (El-17.2a).
Figure imgf000217_0002
CH3S03H
[0290] To a stirred solution of (3S,4R)-4-methylbenzyl 3-fluoro-4-((fluro[3,2-b]pyridin-5- ylamino)methyl)piperidine-l-carboxylate (82 mg, 0.21 mmol) in DCM (3.0 mL) was added methanolic methanesulfonic acid (1.05 mL, 0.2 M, 0.21 mmol). The mixture was stirred for 30 min at room temperature, then concentrated to afford the title product as a pale yellow powder (96 mg, 95%). MS (ESI) calcd for C22H24FN303: 397.2; found: 398.2 [M+H]. *H NMR (400 MHz, CD3OD) δ 8.18 (d, J = 9.2 Hz, 1H), 8.13 (d, J = 2.4 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.99 (d, J = 2.4 Hz, 1H), 6.92 (d, J = 9.2 Hz, 1H), 5.08 (s, 2H), 4.87-4.72 (m, 1H), 4.53-4.44 (m, 1H), 4.30-4.24 (m, 1H), 3.58-3.46 (m, 1H), 3.44-3.37 (m, 1H), 3.18-2.85 (m, 2H), 2.71 (s, 3H), 2.33 (s, 3H), 2.23-2.06 (m, 1H), 1.77-1.56 (m, 2H).
EXAMPLE 1.38. (3S,4 )-4-methylbenzyl 3-fluoro-4-((pyrazolo[l,5-a]pyrimidin-5-ylamino)-methyl)- piperidine-l-carboxylate (El-13.2).
Figure imgf000218_0001
[0291] To a stirred solution of (3S,4R)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (450 mg, 1.61 mmol) in n-BuOH (8.0 mL) were added DIPEA (0.56 mL, 3.21 mmol) and 5-chloropyrazolo[l,5-a]pyrimidine (271 mg, 1.77 mmol). The reaction mixture was heated to 110 °C with stirring overnight at 110 °C. The mixture was allowed to cool to room temperature and concentrated. The residue was purified by column chromatography over silica gel (DCM / MeOH = 75/1) to afford the title compound as a white powder (387 mg, 69%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.5[M+H]. *H NM R (400 MHz, CDCI3) δ 8.21 (d, J = 7.2 Hz, 1H), 7.84 (d, J = 2.0 Hz, 1H), 7.25 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.11 (d, J = 2.0 Hz, 1H), 6.01 (d, J = 7.2 Hz, 1H), 5.15-5.05 (m, 3H), 4.90-4.42 (m, 2H), 4.40-4.20 (m, 1H), 3.60-3.40 (m, 2H), 3.02-2.72 (m, 2H), 2.35 (s, 3H), 2.25-2.07 (m, 1H), 1.75-1.55 (m, 2H).
EXAMPLE 1.38a. (3S,4R)-4-methylbenzyl 3-fluoro-4-((pyrazolo[l,5-a]pyrimidin-5-ylamino)methyl)- piperidine-l-carboxylate methanesulfonate (El-13.2a).
Figure imgf000218_0002
CH3SO3H [0292] To a stirred solution of (3S,4R)-4-(trifluoromethoxy)benzyl 4-(([l,2,4]triazolo[4,3-a]pyrazin-8- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (380 mg, 0.96 mmol) in MeOH (5.0 m L) was added CH3S03H in MeOH (1.0M, 0.96 mL, 0.96 mmol) at rt. After stirring for 30 min, the mixture was concentrated to afford the product as an off-white powder (459 mg, 97%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.4[M+H]. *H N M R (400 M Hz, CD3OD) δ 8.65 (d, J = 7.2 Hz, 1H), 8.00 (s, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.51 (d, J = 7.2 Hz, 1H), 6.36 (s, 1H), 5.08 (m, 2H), 4.86-4.71 (m, 1H), 4.54-4.44 (m, 1H), 4.32-4.23 (m, 1H), 3.65-3.55 (m, 1H), 3.52-3.44 (m, 1H), 3.20- 2.84 (m, 2H), 2.71 (s, 3H), 2.33 (s, 3H), 2.26-2.08 (m, 1H), 1.78-1.56 (m, 2H).
EXAM PLE 1.39. (3S, 4 ?)-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-6-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-19.2).
Figure imgf000219_0001
[0293] To a stirred suspension of (3S,4/?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (200 mg, 0.63 mmol) in isopropanol (5 mL) was added 6-chloro-lH- pyrazolo[3,4-d]pyrimidine (88 mg, 0.57 mmol) and TEA (0.17 mL, 1.26 mmol) at room temperature. The mixture was heated to 80 °C under nitrogen with stirring overnight. The mixture was allowed to cool to room temperature and concentrated in vacuo. The residue was dissolved in ethyl acetate and the resulting solution was washed with water, brine, dried over Na2S04 and concentrated under reduced pressure. The obtained residue was purified by column chromatography over silica gel (3% MeOH-DCM ) to afford the title compound as an off-white powder (122 mg, 58%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.4 [M+H]. *H N M R (400 M Hz, CD3OD) δ 8.77 (s, 1H), 7.91 (s, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.49 (s, 1H), 5.07 (s, 2H), 4.84-4.71 (m, 1H), 4.47-4.41 (m, 1H), 4.25-4.21 (m, 1H), 3.51-3.41 (m, 2H), 3.13-2.79 (m, 2H), 2.33 (s, 3H), 2.22-2.06 (m, 1H), 1.62- 1.52 (m, 2H).
EXAM PLE 1.39a. (3S, 4 ?)-4-methylbenzyl 4-((lH-pyrazolo[3,4-d] pyrimidin-6-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate methanesulfonate (El-19.2a).
Figure imgf000220_0001
CH3S03H
[0294] To a solution of (3S, 4 ?)-4-methylbenzyl 4-((lH-pyrazolo[3,4-d]pyrimidin-6-ylamino) methyl)-3- fluoropiperidine-l-carboxylate (119 mg, 0.30 mmol) in DCM/MeOH (1/1, 4 mL) was added methylsulfonic acid in MeOH (0.6 mL, 0.5 M, 0.30 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as an off-white powder (142 mg, 97%). MS (ESI) calcd for C20H23FN6O2: 398.2; found: 399.5 [M+H]. *H NM (400 MHz, CD3OD) δ 9.03 (s, 1H), 8.30 (s, 1H), 7.23 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.87-4.73 (m, 1H), 4.49-4.42 (m, 1H), 4.26-4.23 (m, 1H), 3.64-3.52 (m, 2H), 3.13-2.81 (m, 2H), 2.73 (s, 3H), 2.33 (s, 3H), 2.25-2.08 (m, 1H), 1.64-1.56 (m, 2H).
EXAMPLE 1.40. (3S, 4 ?)-4-methylbenzyl-3-fluoro-4-(((l-methyl-lH-pyrazolo-[3,4-d]pyrimidin-6-yl)- amino)methyl)piperidine-l-carboxylate (El-19.26).
Figure imgf000220_0002
Step 1: 6-chloro-l-methyl-lH-pyrazolo[3,4-d]pyrimidine
Figure imgf000220_0003
[0295] To a stirred solution of 6-chloro-lH-pyrazolo [3,4-d]pyrimidine (500 mg, 3.23 mmol) in DMF (10 mL) was added NaH (117 mg, 4.85 mmol) portionwise at 0 °C under N2 atmosphere. After stirring for 15min, iodomethane (0.24 mL, 3.88 mmol) was then added dropwise and the resulting mixture was stirred at room temperature for an hour. The mixture was quenched by addition of water at 0 °C until no gas was evolved and then extracted with ethyl acetate. The organic phase was dried over anhydrous Na2S04 and concentrated. The residue was purified by column chromatography over silica gel (hexane/ ethylacetate = 5/1) to afford the title compound as a white powder (328 mg, 61%). MS (ESI) calcd for C6H5CI N4: 168.0; found: 169.1, 171.1[M+H]. *H N M (400 M Hz, CDCI3) δ 9.03 (s, 1H), 8.14 (s, 1H), 4.11 (s, 3H).
Step 2: (3S, 4 ?)-4-methylbenzyl-3-fluoro-4-((l-methyl-l/-/-pyrazolo-[3,4-d]pyrimidin-6-ylamino)- methyl)piperidine-l-carboxylate
Figure imgf000221_0001
[0296] To a stirred suspension of (3S,4 ?)-4-methylbenzyl-4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (200 mg, 0.63 mmol) in isopropanol (5 mL) were added 6-chloro-l- methyl-l/-/-pyrazolo[3,4-d]pyrimidine (96 mg, 0.57 mmol) and TEA (0.22 m L, 1.58 mmol). The mixture was heated to 80 °C under nitrogen with stirring overnight. The mixture was then allowed to cool to room temperature and concentrated in vacuo. The resulting residue was dissolved in ethyl acetate. The organic phase was washed with water, brine, dried over Na2S04 and concentrated under reduce pressure. The residue was purified by column chromatography over silica gel (3% MeOH-DCM ) to afford the title compound as a white powder (132 mg, 56%). MS (ESI) calcd for C21H25FN602: 412.2; found: 413.4 [M+H]. *H N M R (400 M Hz, CD3OD) δ 8.72 (s, 1H), 7.89 (s, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.07 (s, 2H), 4.85-4.72 (m, 1H), 4.48-4.41 (m, 1H), 4.25- 4.22 (m, 1H), 3.86 (s, 3H), 3.56-3.43 (m, 2H), 3.13-2.81 (m, 2H), 2.33 (s, 3H), 2.21-2.06 (m, 1H), 1.68- 1.54 (m, 2H).
EXAM PLE 1.40a. (3S, 4 ?)-4-methylbenzyl 3-fluoro-4-((l-methyl-lH-pyrazolo-[3,4-d]pyrimidin-6-ylamino)- methyl)piperidine-l-carboxylate methanesulfonate (El-19.26a).
Figure imgf000222_0001
CH3S03H
[0297] To a stirred solution of (3S, 4 ?)-4-methylbenzyl 3-fluoro-4-((l-methyl-lH-pyrazolo[3,4- d]pyrimidin-6-ylamino)methyl)piperidine-l-carboxylate (121 mg, 0.29 mmol) in DCM/MeOH (1/1, 4 mL) was added methylsulfonic acid in MeOH (580 μί, 0.5 M, 0.29 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as a white powder (143 mg, 96%). MS (ESI) calcd for C21H25FN602: 412.2; found: 413.4 [M+H]. *H NM (400 MHz, CD3OD) δ 8.98 (s, 1H), 8.27 (s, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 5.08 (s, 2H), 4.84-4.74 (m, 1H), 4.49-4.43 (m, 1H), 4.27-4.23 (m, 1H), 3.94 (s, 3H), 3.69-3.53 (m, 2H), 3.14- 2.84 (m, 2H), 2.72 (s, 3H), 2.33 (s, 3H), 2.26-2.10 (m, 1H), 1.67-1.57 (m, 2H).
EXAMPLE 1.41. (3S,4R)-4-methylbenzyl 4-((7H-pyrrolo[2,3-d]pyrimidin-2-ylamino)methyl)-3-fluoro- piperidine-l-carboxylate (El-20.2).
Figure imgf000222_0002
Step 1: 2-chloro-7-tosyl-7H-pyrrolo[2,3-d]pyrimidine
Figure imgf000222_0003
[0298] To a stirred solution of p-toluenesulfonyl chloride (1.36 g, 7.13 mmol) and 2-chloro-7H- pyrrolo[2,3-d]pyrimidine (1.00 g, 6.51 mmol) in acetone (7 mL) was added aqueous sodium hydroxide solution (9.6 mmol, 2 M, 4.8 mL) under ice-water bath cooling. The solution was then stirred at ambient temperature for ca. 3 hours. The formed precipitate was collected by filtration and washed with acetone/water to afford the title product as a white powder (1.72 g, 85%). MS (ESI) calcd for C13H10CIN3O2S: 307.0; found: 308.0 and 310.0 [M+H]. *H NM (400 MHz, CDCI3) δ 8.78 (s, 1H), 8.12 (d, J = 8.4 Hz, 2H), 7.72 (d, J = 4.0 Hz, 1H), 7.35 (d, J = 8.4 Hz, 2H), 6.64 (d, J = 4.0 Hz, 1H), 2.42 (s, 3H).
Step 2: (3S,4R)-4-methylbenzyl 3-fluoro-4-((7-tosyl-7H-pyrrolo[2,3-d]-pyrimidin-2-ylamino)- methyl)piperidine-l-carboxylate
Figure imgf000223_0001
9] To a stirred suspension of (3S,4 ?)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (450 mg, 1.42 mmol) in NMP (3 mL) were added 2-chloro-7-tosyl-7H- pyrrolo[2,3-d]pyrimidine (300 mg, 0.97 mmol) and DIPEA (0.7 mL, 4.0 mmol). The mixture was heated to 100 °C under nitrogen with stirring overnight. The mixture was then allowed to cool to room temperature and diluted with ethyl acetate. The mixture was washed with water, brine, dried over Na2S04 and concentrated under reduce pressure. The residue was purified by column chromatography over silica gel (ethyl acetate/hexane = 1/1) to afford the title compound as a white powder (400 mg, 74%). MS (ESI) calcd for QsHsoFNsC S: 551.2; found: 552.2 [M+H]. *H NMR (400 MHz, CDCI3) δ 8.44 (s, 1H), 7.99 (d, J = 8.0 Hz, 2H), 7.34 (d, J = 4.0 Hz, 1H), 7.29 (d, J = 8.0 Hz, 2H), 7.26 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 6.42 (d, J = 4.0 Hz, 1H), 5.56-5.46 (m, 1H), 5.17-5.06 (m, 2H), 4.90-4.71 (m, 1H), 4.65-4.47 (m, 1H), 4.39-4.23 (m, 1H), 3.55-3.43 (m, 2H), 3.00-2.80 (m, 2H), 2.40 (s, 3H), 2.35 (s, 3H), 2.22-2.08 (m, 1H), 1.73-1.60 (m, 2H).
Step 3: (3S,4R)-4-methylbenzyl 4-((7H-pyrrolo[2,3-d]pyrimidin-2-ylamino)methyl)-3- fluoropiperidine-l-carboxylate
Figure imgf000223_0002
[0300] To a stirred solution of (3S,4R)-4-methylbenzyl 3-fluoro-4-((7-tosyl-7H-pyrrolo-[2,3-d]pyrimidin- 2-ylamino)methyl)piperidine-l-carboxylate (400 mg, 0.73 mmol) in THF (5 mL) was added aqueous sodium hydroxide solution (50%, 5 mL). The mixture thus obtained was stirred at 70 °C for 13 hours. The mixture was neutralized with 1 N aqueous HCI to pH 8 and extracted with ethyl acetate. The organic phases were combined, washed with water, brine, dried over Na2S04 and concentrated. The residue was purified by column chromatography over silica gel (ethyl acetate/hexane = 3/1) to afford the title compound as a white powder (150 mg, 52%). MS (ESI) calcd for C21H24FN5O2: 397.2; found: 398.2 [M+H]. *H NMR (400 MHz, d6-DMSO) δ 11.23 (s, 1H), 8.48 (s, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 6.99 (dd, J = 3.6 and 2.4 Hz, 1H), 6.84-6.78 (m, 1H), 6.26 (dd, J = 3.6 and 2.4 Hz, 1H), 5.02 (s, 2H), 4.89-4.74 (m, 1H), 4.32-4.21 (m, 1H), 4.14-4.04 (m, 1H), 3.32-3.21 (m, 2H), 3.12-2.95 (m, 1H), 2.93-2.73 (m, 1H), 2.29 (s, 3H), 2.14-1.95 (m, 1H), 1.58-1.55 (m, 1H), 1.43-1.32 (m,
1H).
EXAMPLE 1.41a. (3S,4R)-4-methylbenzyl 4-((7H-pyrrolo[2,3-d]pyrimidin-2-ylamino)methyl)-3- fluoropiperidine-l-carboxylate methanesulfonate (El-20.2a).
Figure imgf000224_0001
CH3S03H
[0301] To a stirred solution of (3S,4R)-4-methylbenzyl 4-((7H-pyrrolo[2,3-d]pyrimidin-2- ylamino)methyl)-3-fluoropiperidine-l-carboxylate (136 mg, 0.34 mmol) in DCM/MeOH (1/1, 4 mL) was added methylsulfonic acid (33 mg, 0.34 mmol). The reaction solution was stirred at room temperature for 15 min. The solvent was evaporated to afford the title compound as a white powder (165 mg, 98%). MS (ESI) calcd for C21H24FN502: 397.2; found: 398.3 [M+H]. *H NMR (400 MHz, CD3OD) δ 8.56 (s, 1H), 7.37 (d, J = 4.0 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 2H), 6.59 (d, J = 4.0 Hz, 1H), 5.08 (s, 2H), 4.85-4.73 (m, 1H), 4.49-4.42 (m, 1H), 4.26-4.23 (m, 1H), 3.60- 3.47 (m, 2H), 3.09-2.97 (m, 1H), 2.94-2.83 (m, 1H), 2.71 (s, 3H), 2.33 (s, 3H), 2.22-2.06 (m, 1H), 1.67- 1.57 (m, 2H). EXAMPLE 1.42. (3S,4R)-4-methylbenzyl 3-fluoro-4-((quinazolin-2-ylamino)methyl)-piperidine-l- carboxylate (El-34.2).
M
Figure imgf000225_0001
[0302] To a stirred solution of (3S,4R)-4-methylbenzyl 4-(aminomethyl)-3-fluoropiperidine-l- carboxylate hydrochloride (232 mg, 0.83 mmol) in n-BuOH (5.0 mL) were added DIPEA (0.29 mL , 0.91 mmol) and 2-chloroquinazoline (150 mg, 0.91 mmol). The reaction mixture was heated to 100 °C under N2 atmosphere with stirring overnight. The mixture was cooled, concentrated in vacuo, and the resulting residue was purified by column chromatography over silica gel (DCM / MeOH = 100/1) to afford the title compound as a white powder (259 mg, 77%). MS (ESI) calcd for C23H25FN4O2: 408.2; found: 409.2[M+H]. *H NMR (400 MHz, CDCI3) δ 8.99 (s, 1H), 7.71-7.65 (m, 2H), 7.58 (d, J = 8.4 Hz, 1H), 7.28-7.22 (m, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.58-5.51 (m, 1H), 5.16-5.06 (m, 2H), 4.95-4.70 (m, 1H), 4.68-4.42 (m, 1H), 4.41-4.19 (m, 1H), 3.68-3.50 (m, 2H), 3.00-2.72 (m, 2H), 2.35 (s, 3H), 2.25- 2.05 (m, 1H), 1.75-1.60 (m, 2H).
EXAMPLE 2. Assays.
EXAMPLE 2.1. NR2B Antagonist Activity.
[0303] HEK293 cell lines stably expressing cloned human NR1/NR2B and NR1/NR2A, respectively, were established according to standard previously described methods (Hansen et al., Comb. Chem High Throughput Screen. 11:304, 2008). Activation of the NR2A or NR2B subtype of NMDA receptor with glutamate as an agonist and glycine co-agonist on these cells results in calcium influx, which can be monitored with fluorescent indicator Fluo-4. A cell based assay has been implemented to evaluate the effect of a compound on NR2A and NR2B receptors by measuring the fluorescent changes (Hansen et al., Comb. Chem High Throughput Screen. 11:304, 2008).
[0304] HEK293 cells stably expressing NR2A or NR2B receptors were cultured at 37 °C in a humidified C02 incubator in DM EM supplemented with 10% fetal bovine serum (FBS) (Hyclone), 10 μΜ MK801 (Sigma-Aldrich) and 50 μΜ AP-5 (Tocris). For experiments, the cells were seeded onto poly-D-lysine- coated 96-well black plates with clear bottom (Corning) at a density of ~50,000 cells/well. After overnight culture, the growth medium was removed from the wells and the cells were incubated at 37 °C for 60 min in Hanks buffer containing 4 μΜ fluo-4-AM (Invitrogen) and 0.1% bovine serum albumin (BSA). After dye-loading, the cells were washed three times with Hanks buffer and incubated for 10 min at room temperature with various concentrations of test compounds prepared in Hanks buffer with 0.1% BSA. The cell plates were placed onto FDSS μΟθΙΙ fluorescence reader (Hamamatsu). After 20 sec reading of background fluorescence, agonist glutamate at final 100 μΜ and co-agonist glycine at final 50 μΜ were added to the cells to activate the receptor, and the resulting fluorescence changes were recorded and quantified. Based on the changes in fluorescence intensity, the pharmacological effect of test compounds were analyzed and the IC50 values derived from a non-linear least squares fitting of the concentration-dependent response to a standard logistic equation using Prism (Graphpad, Inc):
Amplitude = Max Amplitude/(l+(IC50/[antagonist])n). Results are shown in the table below.
Figure imgf000226_0001
Figure imgf000227_0001
Figure imgf000228_0001
Figure imgf000229_0001
Figure imgf000230_0001
Figure imgf000231_0001
Figure imgf000232_0001
EXAMPLE 2.2. Forced Swim Test.
[0305] The forced swim test was used to evaluate antidepressant activity (Porsolt et al., 1977 Arch. Int.
Pharmacodyn. 229: 327-336). Mice that are forced to swim in a situation from which they cannot escape, rapidly become immobile. Drugs with antidepressant activity, such as imipramine, reduce the amount of time spent in the immobile state. Therefore, the amount of immobility time during a test conducted after drug administration represents a useful indicator of antidepressant activity (Lucki et el., 2001, Psychopharmacology 155:315-322).
[0306] Male mice (strain NLMN) weighing 25-35 g were used for testing. All animals were housed in a temperature (22-24 °C) and humidity (50-60%) controlled environment with free access to food and water on a 12-hour light-dark cycle. Test compounds were dissolved in 0.5% dimethylsulfoxide, 4% hydroxypropyl" -cyclodextrin water to generate the appropriate dosing solution. Drugs were administered by intraperitoneal injection at a dose volume of 10 mL/kg. Testing was initiated 20-60 minutes after dosing. Testing for antidepressant activity was conducted as described by Darci et al. (Darci et al., 2004, Eur. J. Pharmacol. 499:135-146). Mice were placed in a white plastic cylinder 20 cm high with a diameter of 21 cm containing 10 cm of water at 25 ± 2 °C. The mice were videotaped for 6 minutes, and the last 4 minutes of video were analyzed by a blinded observer off-line. The observer judged the animal to be immobile when it ceased all activity (struggling, swimming, jumping etc.) and floated passively atop the water. The amount of time each animal spent in the immobile state was recorded and used for statistical analysis of compound effect. Group differences were evaluated by student's t-test or one-way ANOVA followed by post-hoc Dunnett's test.
[0307] In both Examples 2.2.1 and 2.2.2, the positive control compound, imipramine (32 mg/kg, IP) showed the expected antidepressant activity (see FIGs. 1 and 2).
EXAMPLE 2.2.1. Compound El-1.2.
[0308] Results are shown in FIG. 1. Bars represent the mean ± SEM immobility time for each dose group (n = 10, ***/**: different from vehicle group, p < 0.001/0.01 respectively, One-way ANOVA, Dunnett's post-test). Doses are given as milligram per kilogram (mpk). The dose of imipramine was 32 mpk.
EXAMPLE 2.2.2. Compound El-2.2.
[0309] Results are shown in FIG. 2. Bars represent the mean ± SEM immobility time for each study group (n = 10, ***/**: different from vehicle group, p < 0.001/0.01 respectively, One-way ANOVA, Dunnett's post-test). Doses are given as milligram per kilogram (mpk). The dose of imipramine was 32 mpk. 0] These results indicate that provided compounds exhibit antidepressant activity when tested in a standard model for human depression.

Claims

WHAT IS CLAI M ED IS:
1. A chemical entity, which is a compound of Formula (I):
Figure imgf000235_0001
a pharmaceutically acceptable salt thereof, wherein: is alkyl, cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl or (heteroaryl)alkyl, wherein each of cycloalkyi, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl and (heteroaryl)alkyl is independently optionally substituted with 1 to 3 groups independently selected from -F, -CI, Ci-C4 alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, -Q alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, CrC4 alkylthio, Ci-C4 alkylsulfonyl and -S(0)2CF3; wherein each instance of R2 and R3 independently is -H or Ci-C4 alkyl, or
Figure imgf000235_0002
Z is 9- or 10-membered bicyclic ring system having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S, wherein said ring system : is a heteroaromatic ring system, which ring system is optionally substituted with 1 or 2 Rx groups and optionally substituted with 1 Ra group, wherein each Rx is attached to a ring carbon atom and Ra is attached to a ring nitrogen atom; or is a 5- or 6-membered heteroaryl in which two adjacent ring atoms are linked to form a 5- or 6- membered heterocycle, which ring system is optionally substituted with 1 or 2 Rx groups and optionally substituted with 1 Rb group, wherein each Rx is attached to a ring carbon atom and Rb is attached to a ring nitrogen atom; wherein: each instance of Rx independently is -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -OH, -OCH3, -OCF3 or -CN, or two instances of Rx on the same carbon atom together are =0;
Ra is Ci_4 alkyl, C3.4 cycloalkyl or -S(0)2-C!_4 alkyl; and
Rb is Ci-4 alkyl, C3.4 cycloalkyl, -C(0)-Ci-4 alkyl, -C(0)0-C1 alkyl or -S(0)2-Ci-4 alkyl.
2. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic
heteroaromatic ring system having 1 nitrogen ring atom and 1 oxygen ring heteroatom.
3. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic
heteroaromatic ring system having 2 nitrogen ring atoms.
4. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic
heteroaromatic ring system having 3 nitrogen ring atoms.
5. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic
heteroaromatic ring system having 4 nitrogen ring atoms.
6. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl having 2 or 3 ring nitrogen atoms are linked to form a 6-membered heterocyclyl having 1 nitrogen ring atom.
7. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 5-membered heteroaryl having 2 or 3 ring nitrogen atoms are linked to form a 6-membered heterocycle having 1 nitrogen ring atom and 1 additional ring heteroatom selected from N and O.
8. The chemical entity of claim 1, wherein Z is a 9-membered optionally substituted bicyclic ring system in which two adjacent atoms on a 6-membered heteroaryl having 1 ring nitrogen atom are linked to form a 5-membered heterocycle having 1 oxygen ring atom.
9. The chemical entity of any of claims 1-8, wherein R1 is optionally substituted (aryl)alkyl. 10. The chemical entity of claim 9, wherein R1 is optionally substituted benzyl. The chemical entity of claim 10, wherein the compound of Formula (I) is a compoi Formula (II):
Figure imgf000237_0001
wherein R5, R6 and R7 independently are -H, -F, -CI, C C alkyl, cyclopropyl, -C≡CH, -CFH2, -CF2H, -CF3, -CF2CH3, -CH2CF3, C C4 alkoxy, -OCFH2, -OCF2H, -OCF3, -CN, -N(R2)(R3), -N02, C C4 alkylthio,
C Q alkylsulfonyl or -S(0)2CF3; wherein each instance of R2 and R3 independently is -H or C C alkyl, or
Figure imgf000237_0002
12. The chemical entity of claim 11, wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CF2H, -CF3, -CH2CH3, -CF2CH3, isopropyl, ferf-butyl, cyclopropyl, -OCF3, -OCF2H, -SCH3, -SCH2CH3, -S(0)2CH3, -S(0)2CH2CH3 or -S(0)2CF3.
13. The chemical entity of claim 11, wherein each of R5, R6 and R7 independently is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H, -SCH3, -S(0)2CH3 or -C≡CH.
14. The chemical entity of claim 11, wherein:
R5 is -H, -F, -CI, -CH3, -CFH2, -CF2H, -CF3, -CH2CH3, -CF2CH3, -CH2CF3, cyclopropyl, -OCF3, -OCF2H,
-SCH3, -S(0)2CH3 or -C≡CH; R6 is -H or -F; and R7 is -H, -F, -CI or -CH3.
15. The chemical entity of any of claims 11-14, wherein the compound of Formula (II) is a compound of Formula (lla):
Figure imgf000238_0001
The chemical entity of any of claims 11-14, wherein the compound of Formula (II) is a compound of Formula (lla-1):
Figure imgf000238_0002
The chemical entity of any of claims 11-14, wherein the compound of Formula (II) is a compound of Formula (lla-2):
Figure imgf000238_0003
18. A pharmaceutical composition comprising the chemical entity of any one of claims 1-17 and a pharmaceutically acceptable carrier.
19. The pharmaceutical composition of claim 18, which is suitable for oral administration.
20. A method of treating a disease or disorder responsive to NR2B antagonism in a subject in need of such treatment, comprising administering an effective amount of the chemical entity of any one of claims 1-17.
The method of claim 20, wherein the disease or disorder is depression, pain, Parkinson's disease, Huntington's disease, Alzheimer's disease, cerebral ischaemia, traumatic brain injury, epilepsy or migraine.
The method of claim 21, wherein the disease or disorder is depressi
PCT/US2015/065829 2014-12-16 2015-12-15 Bicyclic azaheterocyclic compounds as nr2b nmda receptor antagonists Ceased WO2016100349A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201462092791P 2014-12-16 2014-12-16
US62/092,791 2014-12-16

Publications (2)

Publication Number Publication Date
WO2016100349A2 true WO2016100349A2 (en) 2016-06-23
WO2016100349A3 WO2016100349A3 (en) 2016-08-18

Family

ID=56127835

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2015/065829 Ceased WO2016100349A2 (en) 2014-12-16 2015-12-15 Bicyclic azaheterocyclic compounds as nr2b nmda receptor antagonists

Country Status (1)

Country Link
WO (1) WO2016100349A2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10221182B2 (en) 2015-02-04 2019-03-05 Rugen Holdings (Cayman) Limited 3,3-difluoro-piperidine derivatives as NR2B NMDA receptor antagonists
US10294230B2 (en) 2015-06-01 2019-05-21 Rugen Holdings (Cayman) Limited 3,3-difluoropiperidine carbamate heterocyclic compounds as NR2B NMDA receptor antagonists
US10420768B2 (en) 2014-09-15 2019-09-24 Rugen Holdings (Cayman) Limited Pyrrolopyrimidine derivatives as NR2B NMDA receptor antagonists
US11000526B2 (en) 2016-11-22 2021-05-11 Rugen Holdings (Cayman) Limited Treatment of autism spectrum disorders, obsessive-compulsive disorder and anxiety disorders
CN114213424A (en) * 2021-12-30 2022-03-22 杭州澳赛诺生物科技有限公司 Synthetic method of furan [3, 2-b ] pyridine derivative
US11376258B2 (en) 2019-06-04 2022-07-05 Boehringer Ingelheim International Gmbh Purine derivatives and the use thereof as medicament
US12398143B2 (en) 2019-06-04 2025-08-26 Boehringer Ingelheim International Gmbh Imidazopyrazine derivatives and the use thereof as medicament

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6476041B1 (en) * 1999-10-29 2002-11-05 Merck & Co., Inc. 1,4 substituted piperidinyl NMDA/NR2B antagonists
YU64303A (en) * 2001-02-23 2006-05-25 Merck & Co.Inc. N-substituted nonaryl-heterocyclic nmda/nr2b antagonists
US7592360B2 (en) * 2003-06-04 2009-09-22 Merck & Co., Inc. 3-fluoro-piperidines as NMDA/NR2B antagonists
JPWO2007099828A1 (en) * 2006-02-23 2009-07-16 塩野義製薬株式会社 Nitrogen-containing heterocyclic derivatives substituted with cyclic groups

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10420768B2 (en) 2014-09-15 2019-09-24 Rugen Holdings (Cayman) Limited Pyrrolopyrimidine derivatives as NR2B NMDA receptor antagonists
US10221182B2 (en) 2015-02-04 2019-03-05 Rugen Holdings (Cayman) Limited 3,3-difluoro-piperidine derivatives as NR2B NMDA receptor antagonists
US10294230B2 (en) 2015-06-01 2019-05-21 Rugen Holdings (Cayman) Limited 3,3-difluoropiperidine carbamate heterocyclic compounds as NR2B NMDA receptor antagonists
US10584127B2 (en) 2015-06-01 2020-03-10 Rugen Holdings (Cayman) Limited 3,3-difluoropiperidine carbamate heterocyclic compounds as NR2B NMDA receptor antagonists
US11136328B2 (en) 2015-06-01 2021-10-05 Rugen Holdings (Cayman) Limited 3,3-difluoropiperidine carbamate heterocyclic compounds as NR2B NMDA receptor antagonists
US11000526B2 (en) 2016-11-22 2021-05-11 Rugen Holdings (Cayman) Limited Treatment of autism spectrum disorders, obsessive-compulsive disorder and anxiety disorders
US11752155B2 (en) 2016-11-22 2023-09-12 Rugen Holdings (Cayman) Limited Treatment of autism spectrum disorders, obsessive-compulsive disorder and anxiety disorders
US12527799B2 (en) 2016-11-22 2026-01-20 Rugen Holdings (Cayman) Limited Treatment of autism spectrum disorders, obsessive-compulsive disorder and anxiety disorders
US11376258B2 (en) 2019-06-04 2022-07-05 Boehringer Ingelheim International Gmbh Purine derivatives and the use thereof as medicament
US12398143B2 (en) 2019-06-04 2025-08-26 Boehringer Ingelheim International Gmbh Imidazopyrazine derivatives and the use thereof as medicament
CN114213424A (en) * 2021-12-30 2022-03-22 杭州澳赛诺生物科技有限公司 Synthetic method of furan [3, 2-b ] pyridine derivative

Also Published As

Publication number Publication date
WO2016100349A3 (en) 2016-08-18

Similar Documents

Publication Publication Date Title
JP7248256B2 (en) JAK Kinase Inhibitors, Preparation Methods Thereof, and Uses Thereof in the Pharmaceutical Field
JP5959541B2 (en) Pyrazolo [1,5-A] pyridine as a TRK inhibitor
JP7577655B2 (en) Cyclic urea
WO2016100349A2 (en) Bicyclic azaheterocyclic compounds as nr2b nmda receptor antagonists
US11136328B2 (en) 3,3-difluoropiperidine carbamate heterocyclic compounds as NR2B NMDA receptor antagonists
EA039783B1 (en) TYROSINE AMIDE DERIVATIVES AS Rho KINASE INHIBITORS
US11332459B2 (en) Benzimidazole derivatives and their uses
DK3194403T3 (en) PYRROLOPYRIMIDINE DERIVATIVES AS NR2B NMDA RECEPTOR ANTAGONISTS
CN106795163B (en) Difluoroethylpyridine derivatives as NR2B NMDA receptor antagonists
AU2017216495A1 (en) Metabotropic glutamate receptors 5 modulators and methods of use thereof
US10221182B2 (en) 3,3-difluoro-piperidine derivatives as NR2B NMDA receptor antagonists
AU2021249109A1 (en) N-(heterocyclyl and heterocyclylalkyl)-3-benzylpyridin-2-amine derivatives as SSTR4 agonists
JP7231610B2 (en) Indole derivative and use thereof
HK1253023B (en) 3,3-difluoropiperidine carbamate heterocyclic compounds as nr2b nmda receptor antagonists

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15870879

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15870879

Country of ref document: EP

Kind code of ref document: A2