HK1244803B - Substituted 2-hydrogen-pyrazole derivative serving as anticancer drug - Google Patents

Description

Substituted 2-hydrogen-pyrazole derivatives as anticancer drugs

Field of the Invention

The present invention relates to substituted 2-hydrogen-pyrazole derivatives as selective CDK4/6 inhibitors. In particular, the present invention relates to formula (I) or a pharmaceutically acceptable salt thereof as a selective CDK4/6 inhibitor.

Background of the Invention

The cell cycle is primarily regulated by a series of serine/threonine kinases, also known as cyclin-dependent kinases (CDKs). These kinases, by binding to their corresponding regulatory subunits, cyclins, drive cell cycle progression, genetic transcription, and normal cell division and proliferation. CDK4/6 are key regulators of the cell cycle, triggering the transition from the growth phase (G1) to the DNA replication phase (S1). During cell proliferation, a complex formed by cyclin D and CDK4/6 phosphorylates the retinoblastoma protein (Rb). Phosphorylation of the tumor suppressor protein Rb releases the transcription factor E2F, to which it binds tightly in its unphosphorylated state. E2F activation further drives transcription through the cell cycle restriction point (R point) and progression from G1 to S phase, entering the cell proliferation cycle. Therefore, inhibiting CDK4/6 and preventing it from forming the Cyclin D-CDK4/6 complex can block the progression of the cell cycle from the G1 phase to the S phase, thereby inhibiting tumor proliferation. In estrogen receptor-positive (ER+) breast cancer (BC), overactivity of CDK4/6 is very common, and CDK4/6 is a key downstream target of ER signaling. Preclinical data show that dual inhibition of CDK4/6 and estrogen receptor (ER) signaling has a synergistic effect and can inhibit the growth of estrogen receptor-positive (ER+) breast cancer (BC) cells in the G1 phase.

The CDK4/6 target is a highly competitive area of research and development. Pietzsch summarized the progress in this field in 2010 (Mini-Rev. Med. Chem. 2010, 10, 527-539). Malorni also summarized the latest preclinical and clinical research results of CDK4/6 inhibitors in breast cancer in 2014 (Curr. Opin. Oncol. 2014, 26, 568–575). Extensive research on the CDK4/6 target has led to the development of a series of CDK inhibitors with varying selectivity and the discovery of a few potent and highly selective CDK4/6 inhibitors. Palbociclib (PD0332991) is one of these potent and highly selective CDK4/6 inhibitors and has entered human clinical trials for the treatment of women with advanced or metastatic estrogen receptor (ER+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. Based on interim data from the PALOMA-1 trial, Pfizer submitted a New Drug Application (NDA) for palbociclib to the FDA in August 2014, and the FDA approved palbociclib in February 2015. Two other CDK4/6 inhibitors, Abemaciclib (LY2835219) and LEE-011, have also begun recruiting patients for Phase 3 clinical trials. In addition to breast cancer treatment, these small-molecule heterocyclic compounds are also clinically useful for treating a variety of other cancers. These patents include WO2012018540, WO2012129344, WO2011101409, WO2011130232, WO2010075074, WO2009126584, WO2008032157, and WO2003062236.

To better meet market demand and achieve better tumor treatment results, we hope to develop a new generation of safer, more effective, and highly selective CDK4/6 inhibitors. This invention provides a novel selective CDK4/6 inhibitor and discovers that compounds with this structure exhibit excellent anti-tumor effects.

Summary of the Invention

The purpose of the present invention is to provide a compound represented by formula (I) or a pharmaceutically acceptable salt thereof,

in,

Selected from

R ₁ is selected from H, halogen, OH, NH ₂ , C _1-8 alkyl, C _2-8 alkenyl, C _2-8 alkenyl, C _3-7 cycloalkyl;

R ₂ is selected from H, halogen, C _1-8 alkyl, C _3-7 cycloalkyl, aryl or heteroaryl;

R ₃ is selected from H, halogen, -OR ₈ , -SR ₈ , -N(R ₈ )(R ₉ ) or C _1-3 alkyl;

R ₄ , R ₅ , and R ₆ are each independently selected from H, halogen, OH, NH ₂ , CN, NO ₂ , ═O, or selected from the group consisting of: optionally substituted with 1, 2, or 3 Rs:

C _1-8 alkyl, C _1-8 alkylamino, N,N-di(C _1-8 alkyl)amino, C _1-8 alkoxy-C _1-8 alkyl-, C _1-8 hydroxyalkyl, C _2-8 alkenyl, C _2-8 alkynyl, C _3-7 cycloalkyl, or 3-7 membered heterocycloalkyl;

Optionally, any two of R ₄ , R ₅ , and R ₆ may together form a 3- to 7-membered ring;

R ₇ is selected from H, halogen, -OR ₈ , -SR ₈ , -N(R ₈ )(R ₉ ) or C _3-7 cycloalkyl;

X ₁ , X ₂ , X ₃ and X ₄ are each independently selected from N or C(R ₁₀ );

_X7 is selected from carbonyl or C( _R11 )( _R12 );

W is selected from O, S, or a single bond;

T is selected from N or C(R ₁₀ ), and, when W is selected from O or S, T is not N;

Q is selected from N or C(R ₁₀ );

m and n are independently selected from 0, 1, or 2;

R ₈ and R ₉ are independently selected from H, C _1-8 alkyl, and C _3-7 cycloalkyl;

R is selected from F, Cl, Br, I, NH ₂ , CN, OH, CF ₃ , CHF ₂ , CH ₂ F, NHCH ₃ , N(CH ₃ ) ₂ ;

Optionally, R ₈ and R ₉ are linked to the same atom to form a 3-7 membered ring containing 1-4 heteroatoms;

"Hetero" or "heteroatom" represents O, S, S(=O), S(=O) ₂ or N;

R ₁₀ is selected from H, halogen, OH, NH ₂ , CN, C _1-6 alkyl, C _1-6 alkoxy, C _3-5 cycloalkyl, CN, -OR ₈ , -SR ₈ , -N(R ₈ )(R ₉ ), -C(═O)R ₈ , -C(═O)OR ₈ , -C(═O)N(R ₈ )(R ₉ ), -S(═O)R ₈ , -S(═O) ₂ R ₈ , -S(═O)N(R ₈ )(R ₉ ) or -S(═O) ₂ N(R ₈ )(R ₉ );

R ₁₁ and R ₁₂ are each independently selected from H, OH, halogen, C _1-8 alkyl or C _3-7 cycloalkyl;

Optionally, R ₄ and R ₁₀ are linked to the same atom to form a 3-7 membered ring;

Optionally, the structural unit may be replaced by

In some embodiments of the present invention, the above-mentioned R ₁ is selected from isopropyl, 2-propenyl or allyl.

In some embodiments of the present invention, the above _R2 is selected from methyl and phenyl.

In some embodiments of the present invention, the above R ₃ is selected from F.

In some embodiments of the present invention, R ₄ , R ₅ , and R ₆ are independently selected from H, halogen, OH, NH ₂ , Me, Et, CN, NO ₂ ,

In some embodiments of the present invention, the above R ₇ is selected from H, F or Cl.

In some embodiments of the present invention, the structural unit is selected from

In some embodiments of the present invention, R ₁₀ is selected from H, OH, NH ₂ , F, Cl, CN, or Me.

In some embodiments of the present invention, _X4 is selected from N or CH.

In some embodiments of the present invention, the structural unit is selected from

In some embodiments of the present invention, the structural unit is selected from

The compound of the present invention is selected from:

Definition and Description

Unless otherwise indicated, the following terms and phrases used herein are intended to have the following meanings. A particular term or phrase should not be construed as indefinite or unclear unless specifically defined, but rather should be understood in accordance with its ordinary meaning. When a trade name appears in this document, it is intended to refer to the corresponding commercial product or its active ingredient.

_C1-8 represents the number of carbon atoms in the hydrocarbon group. For example, _C1 represents only one carbon atom, _C2 represents two carbon atoms, and so on.

In the compound of formula (I), the term "C _1-8 alkyl" means a straight chain or directly connected hydrocarbon group containing 1 to 8 carbon atoms, including, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, etc.

"C _2-8 alkenyl" refers to a straight-chain or branched hydrocarbon group containing 2 to 8 carbon atoms and one double bond, including ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl and the like.

"C _2-8 alkynyl" refers to a straight-chain or branched hydrocarbon group containing 2 to 8 carbon atoms and one triple bond, and includes ethynyl, propynyl, 1-butynyl, 2-butynyl and the like.

The "C _3-7 cycloalkyl group" refers to a monocyclic or bicyclic hydrocarbon group containing 3 to 7 carbon atoms, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

The term "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions and/or dosage forms which, within the scope of sound medical judgment, are suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response or other problems or complications, commensurate with a reasonable benefit/risk ratio.

The term "pharmaceutically acceptable salt" refers to salts of the compounds of the present invention, prepared by reacting the compounds of the present invention with relatively nontoxic acids or bases. When the compounds of the present invention contain relatively acidic functional groups, base addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of base in neat solution or in a suitable inert solvent. Pharmaceutically acceptable base addition salts include sodium, potassium, calcium, ammonium, organic amine, or magnesium salts, or similar salts. When the compounds of the present invention contain relatively basic functional groups, acid addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of acid in neat solution or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include inorganic acid salts such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, bicarbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, bisulfate, hydroiodic acid, phosphorous acid, and the like; and organic acid salts such as acetic acid, propionic acid, isobutyric acid, maleic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, and methanesulfonic acid; and salts of amino acids such as arginine, and organic acids such as glucuronic acid (see Berge et al., "Pharmaceutical Salts", Journal of Pharmaceutical Science 66: 1-19 (1977)). Certain specific compounds of the present invention contain both basic and acidic functional groups and can be converted into either base or acid addition salts.

Preferably, the neutral form of the compound is regenerated by contacting the salt with a base or acid in a conventional manner and isolating the parent compound. The parent form of the compound differs from its various salt forms in certain physical properties, such as solubility in polar solvents.

As used herein, "pharmaceutically acceptable salts" are derivatives of the compounds of the present invention wherein the parent compound is modified by acid or base salt formation. Examples of pharmaceutically acceptable salts include, but are not limited to, inorganic or organic acid salts of bases such as amines, alkali metal or organic salts of acids such as carboxylic acids, and the like. Pharmaceutically acceptable salts include conventional non-toxic salts or quaternary ammonium salts of the parent compound, such as salts formed with non-toxic inorganic or organic acids. Conventional non-toxic salts include, but are not limited to, those derived from inorganic and organic acids selected from the group consisting of 2-acetoxybenzoic acid, 2-hydroxyethanesulfonic acid, acetic acid, ascorbic acid, benzenesulfonic acid, benzoic acid, bicarbonate, carbonic acid, citric acid, edetic acid, ethanedisulfonic acid, ethanesulfonic acid, fumaric acid, glucoheptose, gluconic acid, glutamic acid, glycolic acid, hydrobromic acid, hydrochloric acid, hydroiodide, hydroxy, hydroxynaphthoic acid, isethionic acid, lactic acid, lactose, dodecylsulfonic acid, maleic acid, malic acid, mandelic acid, methanesulfonic acid, nitric acid, oxalic acid, pamoic acid, pantothenic acid, phenylacetic acid, phosphoric acid, polygalacturonic acid, propionic acid, salicylic acid, stearic acid, acetic acid, succinic acid, sulfamic acid, p-aminobenzenesulfonic acid, sulfuric acid, tannin, tartaric acid, and p-toluenesulfonic acid.

The pharmaceutically acceptable salts of the present invention can be synthesized from parent compounds containing acid radicals or bases by conventional chemical methods. Generally, such salts are prepared by reacting the free acid or base form of these compounds with a stoichiometric amount of an appropriate base or acid in water or an organic solvent, or a mixture of the two. Generally, non-aqueous media such as ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred.

In addition to the form of salts, the compounds provided by the present invention also exist in prodrug form. The prodrugs of the compounds described herein easily undergo chemical changes under physiological conditions to be converted into the compounds of the present invention. In addition, prodrugs can be converted to the compounds of the present invention by chemical or biochemical methods in an in vivo environment.

Certain compounds of the present invention may exist in unsolvated forms as well as solvated forms, including hydrates. In general, the solvated forms are equivalent to the unsolvated forms and are encompassed within the scope of the present invention.

Certain compounds of the present invention may have asymmetric carbon atoms (optical centers) or double bonds. Racemates, diastereomers, geometric isomers and individual isomers are all within the scope of the present invention.

The diagrammatic representations of racemic, ambiscalemic, scalemic, or enantiomerically pure compounds herein are adapted from Maehr, J. Chem. Ed. 1985, 62:114-120. Unless otherwise indicated, wedge-shaped and dashed bonds are used to represent the absolute configuration at a stereocenter. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, they are intended to include both E and Z geometric isomers unless otherwise specified. Likewise, all tautomeric forms are intended to be encompassed within the scope of this invention.

The compounds of the present invention may exist in specific geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis- and trans-isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, and racemic mixtures and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the present invention. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomers and mixtures thereof are encompassed within the scope of the present invention.

Optically active (R)- and (S)-isomers, as well as D and L isomers, can be prepared by chiral synthesis or chiral reagents or other conventional techniques. If one enantiomer of a compound of the present invention is desired, it can be prepared by asymmetric synthesis or derivatization with a chiral auxiliary, wherein the resulting diastereomeric mixture is separated and the auxiliary group is cleaved to provide the pure desired enantiomer. Alternatively, when the molecule contains a basic functional group (such as an amino group) or an acidic functional group (such as a carboxyl group), a diastereomeric salt is formed with an appropriate optically active acid or base, and then the diastereoisomers are resolved by methods known in the art, and then the pure enantiomer is recovered. In addition, the separation of enantiomers and diastereomers is typically accomplished using chromatography, which employs a chiral stationary phase and is optionally combined with a chemical derivatization method (e.g., carbamate formation from an amine).

The compounds of the present invention may contain unnatural proportions of atomic isotopes at one or more of the atoms comprising the compound. For example, the compounds may be labeled with radioactive isotopes, such as tritium ( ³ H), iodine-125 ( ¹²⁵ I), or C-14 ( ¹⁴ C). All isotopic variations of the compounds of the present invention, whether radioactive or not, are included within the scope of the present invention.

The term "pharmaceutically acceptable carrier" refers to any formulation or carrier medium that can deliver an effective amount of the active substance of the present invention, does not interfere with the biological activity of the active substance, and has no toxic side effects on the host or patient. Representative carriers include water, oils, vegetables and minerals, cream bases, lotion bases, ointment bases, etc. These bases include suspending agents, viscosity increasing agents, transdermal enhancers, etc. Their preparations are well known to those skilled in the art of cosmetics or topical medicine. For additional information about carriers, reference can be made to Remington: The Science and Practice of Pharmacy, 21st Ed., Lippincott, Williams & Wilkins (2005), the contents of which are incorporated herein by reference.

The term "excipient" generally refers to a carrier, diluent and/or vehicle required to formulate an effective pharmaceutical composition.

With respect to a drug or pharmacologically active agent, the term "effective amount" or "therapeutically effective amount" refers to a non-toxic amount of the drug or agent sufficient to achieve the intended effect. For the oral dosage forms of the present invention, an "effective amount" of an active substance in the composition means the amount required to achieve the intended effect when used in combination with another active substance in the composition. The determination of an effective amount varies from person to person, depending on the age and general condition of the recipient, as well as the specific active substance. The appropriate effective amount in each individual case can be determined by those skilled in the art through routine experimentation.

The terms "active ingredient," "therapeutic agent," "active substance," or "active agent" refer to a chemical entity that is effective in treating a target disorder, disease, or condition.

The term "substituted" means that any one or more hydrogen atoms on a particular atom are replaced by a substituent, including deuterium and hydrogen variants, as long as the valence state of the particular atom is normal and the substituted compound is stable. When the substituent is a keto group (i.e., =0), it means that two hydrogen atoms are replaced. Keto substitution does not occur on aromatic groups. The term "optionally substituted" means that it may be substituted or unsubstituted, and unless otherwise specified, the type and number of substituents can be any chemically feasible basis.

When any variable (e.g., R) occurs more than once in a compound's composition or structure, its definition at each occurrence is independent. Thus, for example, if a group is substituted with 0-2 Rs, the group may be optionally substituted with up to two Rs, with each occurrence of R being an independent choice. Furthermore, combinations of substituents and/or their variants are permissible only if such combinations result in stable compounds.

When a substituent's bond crosses two atoms on a ring, the substituent may be bonded to any atom on the ring. When a substituent is listed without specifying the atom through which it is bonded to a compound included but not specifically mentioned in the general chemical formula, the substituent may be bonded to any atom therein. Combinations of substituents and/or their variants are permitted only if such combinations result in stable compounds. For example, a structural unit may indicate that substitution may occur at any position on a cyclohexyl group or a cyclohexadiene group.

Substituents of alkyl and heteroalkyl radicals are generally referred to as "alkyl substituents" and may be selected from, but are not limited to, one or more of the following groups: -R', -OR', =O, =NR', =N-OR', -NR'R", -SR', halogen, -SiR'R"R"', OC(O)R', -C(O) _R ', -CO2R', -CONR'R", -OC(O)NR'R", -NR"C(O)R', NR'C(O)NR"R"', -NR"C(O) _2R ', -NR""'-C(NR'R"R'")=NR"", NR""C(NR'R")=NR'", -S(O)R', -S(O) _2R ', -S(O) _2NR'R ", NR" _SO2R ', -CN, _-NO2 , _-N3 , -CH(Ph), _2- and fluoro(C ₁ -C ₄ )alkyl, the number of substituents is 0 to (2m' + 1), where m' is the total number of carbon atoms in such radicals. R', R", R'', R"" and R""' are each independently preferably hydrogen, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl (e.g., aryl substituted with 1 to 3 halogens), substituted or unsubstituted alkyl, alkoxy, thioalkoxy or aralkyl. When a compound of the present invention includes more than one R group, for example, each R group is independently selected, as are each of these groups when more than one R', R", R'', R"" and R""' group is present. When R' and R" are attached to the same nitrogen atom, they may be combined with the nitrogen atom to form a 5-, 6- or 7-membered ring. For example, -NR'R" is intended to include but is not limited to 1-pyrrolidinyl and 4-morpholinyl. Based on the above discussion of substituents, those skilled in the art will understand that the term "alkyl" is intended to include groups consisting of carbon atoms bonded to non-hydrogen _groups , such as haloalkyl (e.g., _-CF3 , _-CH2CF3 ) and acyl (e.g., -C(O) _CH3 , -C(O) _CF3 , -C(O) _CH2OCH3 , _etc. ).

Similar to the substituents described for alkyl radicals, aryl and heteroaryl substituents are generally referred to as "aryl substituents" and are selected from, for example, -R', -OR', -NR'R", -SR', -halogen, -SiR'R"R"', OC(O)R', -C(O)R', -C02R', -CONR'R", -OC(O)NR'R", -NR"C(O)R', NR'C(O)NR"R"', -NR"C(O)2R', -NR""'-C(NR'R"R'")＝NR"", NR""C(NR'R")＝NR'", -S(O)R', -S(O) _2R ', -S(O) _2NR'R ", NR" _SO2R ', -CN, _-NO2 , _-N3 , -CH(Ph) ₂ , fluoro( _C1 - _C4), ... )alkoxy and fluoro(C ₁ -C ₄ )alkyl, and the like, with the number of substituents ranging from 0 to the total number of open valences on the aromatic ring; wherein R', R", R'", R"" and R""' are independently preferably selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl. When a compound of the present invention includes more than one R group, for example, each R group is independently selected, as are each of these groups when more than one R', R", R'", R"" and R""' group is present.

Two substituents on adjacent atoms of an aryl or heteroaryl ring may be optionally substituted with substituents of the formula –TC(O)-(CRR')qU-, where T and U are independently selected from -NR-, -O-, CRR'-, or a single bond, and q is an integer from 0 to 3. Alternatively, two substituents on adjacent atoms of an aryl or heteroaryl ring may be optionally substituted with substituents of the formula –A(CH2)rB-, where A and B are independently selected from –CRR'-, -O-, -NR-, -S-, -S(O)-, S(O) _2- , -S(O) _2NR'- , or a single bond, and r is an integer from 1 to 4. Optionally, one single bond in the new ring thus formed may be replaced with a double bond. Alternatively, two substituents on adjacent atoms of an aryl or heteroaryl ring may be optionally substituted with substituents of the general formula -A(CH2)rB-, wherein s and d are independently selected from integers from 0 to 3, and X is -O-, -NR', -S-, -S(O)-, -S(O) _2- , or -S(O) _2NR'- . The substituents R, R', R", and R'" are independently selected from hydrogen and substituted or unsubstituted _{(C1-C6 )} alkyl.

Unless otherwise specified, the term "halo" or "halogen," by itself or as part of another substituent, means a fluorine, chlorine, bromine, or iodine atom. Additionally, the term "haloalkyl" is intended to include monohaloalkyl and polyhaloalkyl. For example, the term "halo(C ₁ -C ₄ )alkyl" is intended to include, but is not limited to, trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl, and 3-bromopropyl, among others.

Examples of haloalkyl groups include, but are not limited to, trifluoromethyl, trichloromethyl, pentafluoroethyl, and pentachloroethyl. "Alkoxy" represents an alkyl group as described above with the specified number of carbon atoms attached through an oxygen bridge. _C1-6 alkoxy groups include _C1 , _C2 , _C3 , _C4 , _C5 , and _C6 alkoxy groups. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, and S-pentoxy. "Cycloalkyl" includes saturated cyclic groups such as cyclopropyl, cyclobutyl, or cyclopentyl. C3-7 cycloalkyl groups include _C3 , _C4 , _C5 , _C6 , and _C7 cycloalkyl groups. "Alkenyl" includes hydrocarbon chains in a straight or branched configuration with one or more carbon-carbon double bonds present at any stable position along the chain, such as ethenyl and propenyl.

The term "halo" or "halogen" refers to fluorine, chlorine, bromine and iodine.

Unless otherwise specified, the term "hetero" means a heteroatom or heteroatom group (i.e., an atom group containing heteroatoms), including atoms other than carbon (C) and hydrogen (H), and atom groups containing these heteroatoms, for example, including oxygen (O), nitrogen (N), sulfur (S), silicon (Si), germanium (Ge), aluminum (Al), boron (B), -O-, -S-, ＝O, ＝S, -C(＝O)O-, -C(＝O)-, -C(＝S)-, -S(＝O), -S(＝O) _2- , and optionally substituted -C(＝O)N(H)-, -N(H)-, -C(＝NH)-, -S(＝O) _2N (H)-, or -S(＝O)N(H)-.

Unless otherwise specified, "ring" means a substituted or unsubstituted cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, cycloalkynyl, heterocycloalkynyl, aryl or heteroaryl group. The so-called ring includes a monocyclic, linked, spirocyclic, fused or bridged ring. The number of atoms in the ring is usually defined as the number of ring members, for example, "5- to 7-membered ring" means 5 to 7 atoms arranged around. Unless otherwise specified, the ring optionally contains 1 to 3 heteroatoms. Therefore, "5- to 7-membered ring" includes, for example, phenylpyridine and piperidinyl; on the other hand, the term "5- to 7-membered heterocycloalkyl ring" includes pyridinyl and piperidinyl, but does not include phenyl. The term "ring" also includes a ring system containing at least one ring, each of which "rings" independently meets the above definition.

Unless otherwise specified, the term "heterocycle" or "heterocyclyl" means a stable monocyclic, bicyclic, or tricyclic ring containing a heteroatom or heteroatom group, which may be saturated, partially unsaturated, or unsaturated (aromatic), and comprises carbon atoms and 1, 2, 3, or 4 ring heteroatoms independently selected from N, O, and S, wherein any of the above heterocycles may be fused to a benzene ring to form a bicyclic ring. The nitrogen and sulfur heteroatoms may optionally be oxidized (i.e., NO and S(O)p). The nitrogen atom may be substituted or unsubstituted (i.e., N or NR, where R is H or another substituent as defined herein). The heterocycle may be attached to any heteroatom or carbon atom pendant group that forms a stable structure. The heterocycles described herein may be substituted at either the carbon or nitrogen position if the resulting compound is stable. Nitrogen atoms in the heterocycle may be optionally quaternized. Preferably, when the total number of S and O atoms in the heterocycle exceeds 1, the heteroatoms are not adjacent to each other. Another preferred embodiment is that the total number of S and O atoms in the heterocycle does not exceed 1. As used herein, the term "aromatic heterocyclic group" or "heteroaryl" refers to a stable 5-, 6-, or 7-membered monocyclic or bicyclic or 7-, 8-, 9-, or 10-membered bicyclic heterocyclic aromatic ring comprising carbon atoms and 1, 2, 3, or 4 ring heteroatoms independently selected from N, O, and S. The nitrogen atom may be substituted or unsubstituted (i.e., N or NR, where R is H or other substituents as defined herein). The nitrogen and sulfur heteroatoms may be optionally oxidized (i.e., NO and S(O)p). It is noted that the total number of S and O atoms in the aromatic heterocyclic ring does not exceed 1. Bridged rings are also included in the definition of heterocycle. A bridged ring is formed when one or more atoms (i.e., C, O, N, or S) link two non-adjacent carbon atoms or nitrogen atoms. Preferred bridged rings include, but are not limited to, one carbon atom, two carbon atoms, one nitrogen atom, two nitrogen atoms, and a carbon-nitrogen group. It is noted that a bridge always converts a monocyclic ring into a tricyclic ring. In bridged rings, substituents on the ring may also appear on the bridge.

Examples of heterocyclic compounds include, but are not limited to, acridinyl, azcinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzoxazolinyl, benzothiazolyl, benzotriazolyl, benzotetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromene, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, dihydrofuro[2,3-b]tetrahydrofuranyl, furanyl, furazanyl, alkyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolene, indolinyl, indolizinyl, indolyl, 3H-indolyl, isatinoyl, isobenzofuranyl, pyran, isoindolyl, isoindolyl, isoindolyl, indolyl, isoquinolinyl, isothiazolyl, isoxazolyl, methylenedioxyphenyl, morpholinyl, naphthyridinyl, octahydroisoquinolinyl, oxadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidine oxazolyl, isoxazolyl, oxindolyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazine, phenothiazine, benzoxanthinyl, phenoxazinyl, phthalazinyl, piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, piperonyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridoxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2H-pyrrolyl, pyrrolyl, pyrazolyl, quinazolinyl, quinolinyl, 4H-quinolizinyl, quinoxaline The present invention also includes 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, 1,3,4-triazolyl, 1,3,4-thiadiazolyl, 1,4-thiadiazolyl, 1,2,5-thiadiazolyl ...

Unless otherwise specified, the term "hydrocarbyl" or its subordinate concepts (such as alkyl, alkenyl, alkynyl, phenyl, etc.) by itself or as part of another substituent refers to a linear, branched, or cyclic hydrocarbon radical or a combination thereof, which may be fully saturated, mono- or polyunsaturated, mono-, di-, or polysubstituted, monovalent (such as methyl), divalent (such as methylene), or polyvalent (such as methine), and may include divalent or polyvalent radicals, and have a specified number of carbon atoms (such as _C1 - _C10 representing 1 to 10 carbons). "Hydrocarbyl" includes, but is not limited to, aliphatic and aromatic hydrocarbon radicals, the aliphatic hydrocarbon radicals including chain and cyclic ones, specifically including, but not limited to, alkyl, alkenyl, and alkynyl, and the aromatic hydrocarbon radicals including, but not limited to, 6-12 membered aromatic hydrocarbon radicals, such as benzene, naphthalene, etc. In some embodiments, the term "alkyl" refers to a linear or branched radical or a combination thereof, which may be fully saturated, mono- or polyunsaturated, and may include divalent and polyvalent radicals. Examples of saturated hydrocarbon radicals include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, isobutyl, cyclohexyl, (cyclohexyl)methyl, cyclopropylmethyl, and homologues or isomers of radicals such as n-pentyl, n-hexyl, n-heptyl, and n-octyl. Unsaturated alkyl radicals have one or more double or triple bonds, and examples thereof include, but are not limited to, vinyl, 2-propenyl, butenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and higher homologues and isomers.

Unless otherwise specified, the term "heteroalkyl" or its subordinate concepts (such as heteroalkyl, heteroalkenyl, heteroalkynyl, heteroaryl, etc.) by itself or in combination with another term refers to a stable linear, branched or cyclic hydrocarbon radical or combination thereof, consisting of a certain number of carbon atoms and at least one heteroatom. In some embodiments, the term "heteroalkyl" by itself or in combination with another term refers to a stable linear, branched or cyclic hydrocarbon radical or combination thereof, consisting of a certain number of carbon atoms and at least one heteroatom. In a typical embodiment, the heteroatom is selected from B, O, N and S, wherein the nitrogen and sulfur atoms are optionally oxidized and the nitrogen heteroatom is optionally quaternized. The heteroatoms B, O, N and S can be located at any interior position of the heteroalkyl group (including the position at which the hydrocarbon group is attached to the rest of the molecule). Examples include, but are not limited to, _-CH2 - _CH2 -O- _CH3 , _-CH2 - _CH2 -NH- _CH3 , _{-CH2 -CH2} -N( _CH3 ) _-CH3 , -CH2 _- S- _CH2 - _CH3 , -CH2 _{- CH2} , -S(O) _-CH3 , _-CH2- CH2 _- S(O) _{2- CH3} , -CH=CH-O- _CH3 , _-CH2 -CH=N- _OCH3 , and -CH=CH-N( _CH3 ) _-CH3 . Up to two heteroatoms may be consecutive, for example, _-CH2- NH- _OCH3 .

The terms "alkoxy," "alkylamino," and "alkylthio" (or thioalkoxy) are conventional expressions referring to those alkyl groups that are attached to the remainder of the molecule through an oxygen, amino, or sulfur atom, respectively.

Unless otherwise specified, the terms "cycloalkyl," "heterocycloalkyl," or their sub-groups (e.g., aryl, heteroaryl, cycloalkyl, heterocycloalkyl, cycloalkenyl, heterocycloalkenyl, cycloalkynyl, heterocycloalkynyl, etc.), by themselves or in combination with other terms, refer to a cyclized "alkyl" or "heteroalkyl," respectively. Furthermore, in the case of heteroalkyl or heterocycloalkyl (e.g., heteroalkyl, heterocycloalkyl), a heteroatom may occupy the position at which the heterocycle is attached to the remainder of the molecule. Examples of cycloalkyl groups include, but are not limited to, cyclopentyl, cyclohexyl, 1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like. Non-limiting examples of heterocyclic groups include 1-(1,2,5,6-tetrahydropyridinyl), 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-morpholinyl, 3-morpholinyl, tetrahydrofuran-2-yl, tetrahydrofuranindol-3-yl, tetrahydrothiophen-2-yl, tetrahydrothiophen-3-yl, 1-piperazinyl, and 2-piperazinyl.

Unless otherwise specified, the term "aryl" refers to a polyunsaturated aromatic hydrocarbon substituent that can be monosubstituted, disubstituted or polysubstituted, can be monovalent, divalent or polyvalent, can be monocyclic or polycyclic (e.g., 1 to 3 rings; at least one of which is aromatic), which are fused together or covalently linked. The term "heteroaryl" refers to an aryl group (or ring) containing one to four heteroatoms. In an exemplary embodiment, the heteroatoms are selected from B, N, O and S, wherein the nitrogen and sulfur atoms are optionally oxidized and the nitrogen atom is optionally quaternized. The heteroaryl group can be attached to the rest of the molecule through the heteroatom. Non-limiting examples of aryl or heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 3-quinolyl and 6-quinolyl. Substituents for any of the above aryl and heteroaryl ring systems are selected from the group consisting of acceptable substituents described below.

For simplicity, aryl when used in conjunction with other terms (e.g., aryloxy, arylthio, arylalkyl) includes both aryl and heteroaryl rings as defined above. Thus, the term "arylalkyl" is intended to include those radicals in which an aryl group is attached to an alkyl group (e.g., benzyl, phenethyl, pyridylmethyl, etc.), including those alkyl groups in which a carbon atom (e.g., a methylene group) has been replaced by, for example, an oxygen atom, such as phenoxymethyl, 2-pyridyloxymethyl, 3-(1-naphthyloxy)propyl, etc.

The term "leaving group" refers to a functional group or atom that can be replaced by another functional group or atom through a substitution reaction (e.g., a nucleophilic substitution reaction). For example, representative leaving groups include trifluoromethanesulfonate; chlorine, bromine, iodine; sulfonate groups such as methanesulfonate, toluenesulfonate, p-bromobenzenesulfonate, p-toluenesulfonate, etc.; acyloxy groups such as acetoxy and trifluoroacetoxy, etc.

The term "protecting group" includes, but is not limited to, an "amino protecting group," a "hydroxy protecting group," or a "thiol protecting group." The term "amino protecting group" refers to a protecting group suitable for preventing side reactions at the amino nitrogen position. Representative amino protecting groups include, but are not limited to, formyl; acyl, such as alkanoyl (e.g., acetyl, trichloroacetyl, or trifluoroacetyl); alkoxycarbonyl, such as tert-butyloxycarbonyl (Boc); arylmethoxycarbonyl, such as benzyloxycarbonyl (Cbz) and 9-fluorenylmethoxycarbonyl (Fmoc); arylmethyl, such as benzyl (Bn), trityl (Tr), 1,1-bis-(4'-methoxyphenyl)methyl; silyl, such as trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS), and the like. The term "hydroxy protecting group" refers to a protecting group suitable for preventing side reactions at the hydroxyl group. Representative hydroxy protecting groups include, but are not limited to, alkyl groups such as methyl, ethyl and tert-butyl; acyl groups such as alkanoyl (e.g., acetyl); arylmethyl groups such as benzyl (Bn), p-methoxybenzyl (PMB), 9-fluorenylmethyl (Fm) and diphenylmethyl (diphenylmethyl, DPM); silyl groups such as trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS), and the like.

The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthesis methods, and equivalent substitutions well known to those skilled in the art. Preferred embodiments include but are not limited to the examples of the present invention.

The solvents used in the present invention are commercially available. Reactions are generally carried out in anhydrous solvents under an inert nitrogen atmosphere. Proton nuclear magnetic resonance data were recorded on a Bruker Avance III 400 (400 MHz) spectrometer, with chemical shifts expressed in ppm downfield from tetramethylsilane. Mass spectra were measured on an Agilent 1200 Series Plus 6110 (&1956A). LC/MS or Shimadzu MS comprised a DAD: SPD-M20A (LC) and a Shimadzu Micromass 2020 detector. The mass spectrometer was equipped with an electrospray ionization source (ESI) operating in positive or negative mode.

High-performance liquid chromatography (HPLC) analysis was performed on a Shimadzu LC20AB system equipped with a Shimadzu SIL-20A autosampler and a Shimadzu DAD:SPD-M20A detector. An Xtimate C18 column (3 μm packing, 2.1 x 300 mm dimensions) was used. A 0-60AB 6-minute method was used: a linear gradient was applied, starting with 100% A (0.0675% TFA in water) and ending with 60% B (0.0625% TFA in MeCN) over 4.2 minutes, followed by 1 minute of 60% B. The column was then equilibrated for 0.8 minutes to a 100:0 ratio, for a total run time of 6 minutes. 10-80AB_6 minute method: A linear gradient was applied, starting with 90% A (0.0675% TFA in water) and ending with 80% B (0.0625% TFA in acetonitrile) over 4.2 minutes, followed by 1 minute of 80% B. The column was re-equilibrated for 0.8 minutes to a 90:10 ratio, resulting in a total run time of 6 minutes. The column temperature was 50°C, and the flow rate was 0.8 mL/min. The diode array detector scanned from 200 to 400 nm.

Thin layer chromatography (TLC) was performed on silica gel GF254 from Sanpont-group. Spots were usually detected using UV illumination. In some cases, other methods were used to visualize the spots. In these cases, the plates were developed with iodine (prepared by adding approximately 1 g of iodine to 10 g of silica gel and mixing thoroughly), vanillin (prepared by dissolving approximately 1 g of vanillin in 100 mL _of 10% _H2SO4 ), ninhydrin (purchased from Aldrich), _or a special color developer (prepared by thoroughly mixing ( _NH4 ) _6Mo7O24 · _4H2O , 5 g _of ( _NH4 ) _2Ce (IV)( _NO3 ) ₆ , 450 mL _{of H2O} , and _{50 mL} of concentrated _H2SO4 ) to visualize the compounds. Flash column chromatography was performed on a Silicycle 40-63 μm (230-400 mesh) silica gel column using a method similar to the techniques disclosed in Still, W.C.; Kahn, M.; and Mitra, M. Journal of Organic Chemistry, 1978, 43, 2923-2925. Common solvents for flash column chromatography or thin layer chromatography are mixtures of dichloromethane/methanol, ethyl acetate/methanol, and hexane/ethyl acetate.

Preparative chromatography was performed on a Gilson-281Prep LC 322 system using a Gilson UV/VIS-156 detector. Columns used were: Agella Venusil ASB Prep C18, 5 μm, 150 x 21.2 mm; Phenomenex Gemini C18, 5 μm, 150 x 30 mm; Boston Symmetrix C18, 5 μm, 150 x 30 mm; or Phenomenex Synergi C18, 4 μm, 150 x 30 mm. Compounds were eluted with a low gradient of acetonitrile/water containing either 0.05% HCl, 0.25% HCOOH, or 0.5% NH3·H2O at a flow rate of approximately 25 mL/min, with a total run time of 8–15 minutes.

The selective CDK4/6 inhibitors reported in this patent can be used to treat a range of cancers, including breast cancer, non-small cell lung cancer, esophageal cancer, colorectal cancer and acute myeloid leukemia. The selective CDK4/6 inhibitors can be used as a single agent or in combination with other chemotherapeutic agents.

The present invention uses the following abbreviations: MW stands for microwave; rt stands for room temperature; aq stands for aqueous solution; DCM stands for dichloromethane; THF stands for tetrahydrofuran; DMF stands for N,N-dimethylformamide; DMSO stands for dimethyl sulfoxide; EtOAc stands for ethyl acetate; EtOH stands for ethanol; MeOH stands for methanol; _BOC stands for tert-butyloxycarbonyl, which is an amine protecting group; Boc2O stands for di-tert-butyldicarbonate; HOAc stands for acetic acid; TEA stands for trifluoroethylamine; DIPEA stands for diisopropylethylamine; TEA or _Et3N stands for triethylamine; _BnNH2 stands for benzylamine; _PMBNH2 stands for p-methoxybenzylamine; _MnO2 stands for manganese dioxide; HATU stands for O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; _POCl3 stands for phosphorus oxychloride; NaH stands for sodium hydride; _LiAlH4 stands for lithium aluminum tetrahydride; _Pd2 (dba) ₃ represents tris(dibenzylideneacetone)dipalladium; Pd(dppf)Cl ₂ represents [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium; Pd(OAc) ₂ represents palladium acetate; Pd(PPh ₃ ) ₄ represents triphenylphosphine palladium; PPh ₃ represents triphenylphosphine; Xantphos represents 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene; Xphos represents 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl; BINAP represents (±)-2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl; Xphos-PD-G ₂ represents chloro(2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)[2-(2'-amino-1,1'-biphenyl)]palladium(II); NIS represents N-iododibutyrimide; NBS represents N-bromodibutyrimide; NCS represents N-chlorodibutyrimide; t-BuOK represents potassium tert-butoxide; t-BuONa represents sodium tert-butoxide; Cs ₂ CO ₃ represents cesium carbonate; K ₂ CO ₃ represents potassium carbonate; NaBH(OAc) ₃ represents sodium triacetateborohydride; NaBH ₃ CN represents sodium cyanoborohydride; NaHCO3 represents sodium bicarbonate; Na 2 SO 4 represents sodium sulfate; KOAc represents potassium acetate; Xantphos represents 4,5-bis-(diphenylphosphino)-9,9-dimethylxanthene.

The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthesis methods, and equivalent substitutions well known to those skilled in the art. Preferred embodiments include but are not limited to the examples of the present invention.

The compounds of the present invention can be prepared by a series of synthetic steps, wherein _R1 , _R2 , R3, _R4 , _R5 , _R6 , _R7 , _X1 , _X2 , _X3 , X4, _X5 , _X6 , _X7 , m, n, _Q , T and W are _the same as defined above.

Reaction Scheme 1 Preparation of the compound represented by Formula I

When Y=R ₄ , in the reaction shown in Reaction Scheme 1, a 2-hydrogen-pyrazole derivative (A) reacts with a 2-arylamine (B) to produce a compound represented by Formula I. This reaction requires a suitable catalyst (e.g., Pd ₂ (dba) ₃ ), a suitable ligand (e.g., Xantphos), a suitable base (e.g., Cs ₂ CO ₃ ), and a suitable solvent (e.g., 1,4-dioxane). According to Reaction Scheme 1, this reaction is preferably carried out at an elevated temperature.

When QY is N-Boc, in the following reaction shown in Reaction Scheme 1, the compound of Formula I can still be prepared by reacting a 2-hydrogen-pyrazole derivative (A) with a 2-arylamine (B), but the Boc group must be removed under a strong acid (such as TFA) to obtain an amine (C). Finally, the amine (C) undergoes alkylation under reductive amination or nucleophilic substitution conditions (such as NaBH ₃ CN or alkyl halide) to obtain the compound of Formula I.

Reaction Scheme 2 Preparation of 2-hydrogen-pyrazole derivatives (A)

Among them,

In the reaction shown in Reaction Scheme 2, 5-bromo-2-hydro-indazole (D) reacts with an alkyl halide R ₂ X (E) to prepare 5-bromo-2-hydro-indazole (F). This reaction requires a suitable base (such as NaH or MeONa) and a suitable solvent (such as THF). 5-bromo-2-hydro-indazole (G) can be prepared by halogenating 5-bromo-2-hydro-indazole (F). This reaction requires a suitable halogenating agent (such as Br ₂ , NBS or NIS) and a suitable solvent (such as DMF or MeCN). 5-bromo-2-hydro-indazole (I) can be prepared by palladium-catalyzed coupling of a borate ester (H). This reaction requires a suitable catalyst (such as Pd(dppf)Cl ₂ ), a suitable base such as (K ₂ CO ₃ ), and a suitable solvent (such as dioxane and water). 5-Bromo-2-hydrogen-indazole (K) can be prepared by palladium-catalyzed coupling of bis-naphthalene borate (J). This reaction requires a suitable catalyst (e.g., Pd(dppf)Cl ₂ ), a suitable base (e.g., KOAc), and a suitable solvent (e.g., dioxane). 2-Hydrogen-pyrazole derivative (A) can be prepared by palladium-catalyzed coupling of compound (L). This reaction requires a suitable catalyst (e.g., Pd(dppf)Cl ₂ ), a suitable base (e.g., K ₂ CO ₃ ), and a suitable solvent (e.g., dioxane). According to Reaction Scheme 2, this reaction is preferably carried out at an elevated temperature. 2-Hydrogen-pyrazole derivative (A′) can be prepared by rhodium-catalyzed hydrogenation of compound (A). This reaction requires a suitable catalyst (e.g., Rh(PPh ₃ ) ₃ Cl) and a suitable solvent (e.g., tetrahydrofuran). R ₁ ′ is an alkyl group after reduction of R ₁ .

Reaction Scheme 3 Preparation of 2-hydrogen-pyrazole derivatives (A)

Among them,

In the reaction shown in Reaction Scheme 3, Compound (J) reacts with an acyl chloride (N) to produce Compound (O). This reaction requires a suitable base (e.g., LiHMDS) and a suitable solvent (e.g., THF). Compound (O) can be used to produce 2-hydrogen-pyrazole (Q) via a cyclization reaction, which requires a suitable alkylhydrazine (P) and a suitable solvent (e.g., EtOH). 2-hydrogen-pyrazole (R) can be produced via catalytic hydrogenation, which requires a suitable catalyst (e.g., Pd/C) and a suitable solvent (e.g., MeOH). 2-hydrogen-pyrazole derivatives (A) can be produced from Compound (L), which requires a suitable base (e.g., _Et3N ) and a suitable solvent (e.g., THF). According to Reaction Scheme 3, this reaction is preferably carried out at an elevated temperature.

Reaction Scheme 4 Preparation of 2-arylamine (B), where W is S or O, and T is C

In the reaction shown in Reaction Scheme 4, a pyridinium bromide (U) can be prepared by Mitsunobu reaction of 2-bromo-5-hydroxypyridine (S) with a commercially available thiol or alcohol (T). Pyridinium bromide (U) can then be converted to a 2-arylamine (B) under palladium catalysis. This reaction requires a suitable catalyst (e.g., _Pd2 (dba) ₃ ), a suitable base (e.g., LiHMDS), and a suitable solvent (e.g., toluene). According to Reaction Scheme 4, this reaction is preferably carried out at an elevated temperature.

Reaction Scheme 5 Preparation of 2-arylamine (B), where W is a single bond directly connected

In the reaction shown in Reaction Scheme 5, when W is a directly connected single bond, 2-arylamine (B) can be prepared by the following two methods: 1) 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylic acid tert-butyl ester (X) and nitropyridine (W) are first coupled under palladium catalysis, and then the nitro group and double bond are reduced; 2) the bromine atom on the nitropyridine (W) is first replaced by a commercially available amine (V), and then the nitro group is reduced.

DETAILED DESCRIPTION

In order to illustrate the present invention in more detail, the following examples are given, but the scope of the present invention is not limited thereto.

Plan A

General method for preparing intermediate A, intermediate B and intermediate C:

Step 1:

5-Bromo-2(hydrogen)-indazole

To an 85% aqueous solution of hydrazine hydrate (103.00 g, 2.06 mol, 23.20 equiv) was slowly added 5-bromo-2-fluorobenzaldehyde (18.00 g, 88.67 mmol, 1.00 equiv). A white solid slowly precipitated during the addition. The mixture was stirred at 110°C for 16 hours. LCMS indicated that the majority of the target compound was present. The mixture was cooled to 16°C and filtered. The filter cake was washed with water (100 mL) to afford the crude product, which was purified by column chromatography (petroleum ether:ethyl acetate = 3:2) to afford the title compound (6.50 g, 32.99 mmol, 37.21% yield) as a white solid. LCMS (ESI) m/z: 197.1 (M+1).

Step 2:

5-Bromo-2-methyl-2-hydrogen-indazole

At 30 ℃, under nitrogen protection, to 5-bromo-2 hydrogen-indazole (20.00 g, 101.51 mmol, 1.00 equivalent) and sodium methoxide (5.48 g, 5.48 mmol, 5.48 equivalent) in methanol (150.00 ml) solution was added dropwise iodomethane (57.00 g, 401.58 mmol, 3.96 equivalent), and the addition time was controlled to be 1 hour. The mixture was then heated to 85 ℃ and stirred for 5 hours. LCMS showed that the starting material was almost completely consumed and the MS of the desired compound was detected. The mixture was cooled to 16 ℃ and concentrated to give a crude product, which was diluted with 3% NaHCO ₃ aqueous solution (30 ml), extracted with ethyl acetate (80 ml × 2), and the organic phase was concentrated under reduced pressure. The residue was purified by column chromatography (petroleum ether:ethyl acetate = 30:1 to 1:1) to afford the title compound (8.40 g, 39.80 mmol, 39.21% yield) as a gray solid. ^1H NMR (400 MHz, DMSO-d ₆ ) δ 8.33 (s, 1H), 7.95 (s, 1H), 7.58 (d, J = 8.0 Hz, 1H), 7.30 (dd, J = 1.8 Hz, 8 Hz, 1H), 4.18 (s, 1H). LCMS (ESI) m/z: 210.8 (M+1).

Step 3:

5-Bromo-3-iodo-2-methyl-2-hydrogen-indazole

To a solution of 5-bromo-2-methyl-2H-indazole (8.40 g, 39.80 mmol, 1.00 eq) in dichloromethane (90 ml) at 30°C were added pyridine (4.72 g, 59.70 mmol, 1.5 eq) and bis(trifluoroacetyloxy)iodobenzene (20.54 g, 47.76 mmol, 1.20 eq). The mixture was stirred for 0.5 h, then iodine (12.12 g, 47.76 mmol, 1.20 eq) was added and stirring continued for 23.5 h. LCMS indicated the reaction was complete, and the mixture was filtered to give the title compound (8.20 g, crude) as a yellow solid. LCMS (ESI) m/z: 336.9 (M+1). Step 4:

5-Bromo-2-methyl-3-isopropenyl-2-hydrogen-indazole

Under nitrogen, to a solution of 5-bromo-3-iodo-2-methyl-2-hydrogen-indazole (7.68 g, 22.79 mmol, 1.00 equiv) and isopropenyl borate (4.21 g 25.07 mmol, 1.11 equiv) in dioxane (90.00 ml) were added a saturated aqueous solution (30 ml) _{of K2CO3} (9.45 g, 68.38 mmol, 3.00 equiv) and Pd(dppf) _Cl2 · _CH2Cl2 (1.86 g, 2.28 mmol, 0.10 equiv), and the mixture was stirred at 100°C for 3 hours _. TLC showed that the starting material was almost completely reacted. The mixture was cooled to 30°C and filtered. The filtrate was extracted with ethyl acetate (100 mL × 3), washed with water (50 mL × 3), washed with saturated brine (20 mL × ₃ ), dried over anhydrous _Na2SO4 , filtered, and concentrated. The residue was purified by column chromatography (petroleum ether:ethyl acetate = 1:1) to give the title compound (5.36 g, 21.34 mmol, yield 93.66%) as a yellow oil.

Step 5:

2-Methyl-3-isopropenyl-5-boronate-2H-indazole

Under nitrogen, to a solution of 5-bromo-2-methyl-3-isopropenyl-2-hydrogen-indazole (2.80 g, 11.15 mmol, 1.00 equiv) and bispinacol boronate (3.40 g, 13.38 mmol, 1.20 equiv) in dioxane (56.00 ml) were added KOAc (3.28 g, 33.45 mmol, 3.00 equiv) and Pd(dppf) _Cl₂ · _CH₂Cl₂ (1.82 g, 2.23 _mmol , 0.20 equiv). The mixture was stirred at 100° C. for 5 hours. LCMS showed completion of the reaction, and MS of the target compound was detected. The mixture was cooled to 16° C., diluted with ethyl acetate (20 ml), and filtered to obtain a filtrate. The filtrate was purified by column chromatography (petroleum ether:ethyl acetate = 1:1) to afford the title product (3.30 g, 9.96 mmol, 89.33% yield, 90% purity) as a purple solid. LCMS (ESI) m/z: 299.1 (M+1).

Step 6:

5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-isopropenyl-2-hydrogen-indazole

Under nitrogen, to a solution of 2,4-dichloro-5-fluoro-pyrimidine (147.83 mg, 885.34 μmol, 1.20 equiv) and 2-methyl-3-isopropenyl-5-boronate-2-hydrogen-indazole (220.00 mg, 737.78 μmol, 1.00 equiv) in dioxane (4 ml) were added _{K2CO3 (} 305.91 mg, 2.21 mmol, 3.00 equiv) and Pd(dppf) _Cl2 · _CH2Cl2 (120.50 mg, 147.56 μmol, 0.20 equiv), _and the mixture was stirred at 100°C for 3.5 hours. TLC indicated that most of the starting material had been completely reacted, and LCMS indicated that the product was primarily the desired product. The mixture was cooled to 30°C and filtered. The filter cake was washed with ethyl acetate (5 mL). The filtrate was concentrated, and the residue was purified by column chromatography (petroleum ether:ethyl acetate = 1:0 to 6:1) to afford the title product (Intermediate A) (210.0 mg, 693.69 μmol, 94.02% yield) as a bright yellow solid. LCMS (ESI) m/z: 303.0 (M+1).

Step 7:

tert-Butyl 5-fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2-hydrogen-indazol-5-yl)pyrimidin-2-ylcarbamate

To a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-(prop-1-en-2-yl)-2-hydro-indazole (Intermediate A) (1.00 g, 3.30 mmol, 1.00 equiv) in dioxane (15.00 mL) were added tert-butyl carbamate (966.49 mg, 8.25 mmol, 2.50 equiv), potassium carbonate (1.37 g, 9.90 mmol, 3.00 equiv), palladium acetate (74.09 mg, 330.00 μmol, 0.10 equiv), and Xantphos (381.89 mg, 660.00 μmol, 0.20 equiv). The atmosphere was flushed with nitrogen three times and the mixture was stirred at 100°C for 18 hours. LCMS indicated the reaction was complete and product was detected. The solution was cooled to 20°C and filtered. The filtrate was concentrated under reduced pressure to afford the title compound (3.00 g, crude product) as a pale yellow solid. The crude product was used directly in the next step without purification. LCMS (ESI) m/z: 384.1 (M+1).

Step 8:

5-Fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2H-indazol-5-yl)pyrimidin-2-amine

To a solution of tert-butyl 5-fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2-hydrogen-indazol-5-yl)pyrimidin-2-ylcarbamate (3.00 g, 3.31 mmol, 1.00 equiv) in dichloromethane (30.00 mL) was added trifluoroacetic acid (10.00 mL) dropwise. The solution was stirred at 15°C for 1 hour. TLC (petroleum ether:ethyl acetate = 1:1) indicated complete reaction of the starting material. The solution was evaporated to dryness under reduced pressure at 30°C. The crude product was diluted with dichloromethane (100 mL) and washed with saturated sodium bicarbonate (100 mL) and saturated brine (100 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated. The crude product was purified on a silica gel column (petroleum ether:ethyl acetate = 5:1 to 3:1) to afford the title compound (770.00 mg, 2.72 mmol, 82.11% yield) as a brown solid.

Step 9:

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

To a solution of 5-fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2-hydrogen-indazol-5-yl)pyrimidin-2-amine (770.00 mg, 2.72 mmol, 1.00 equiv) in methanol (20.00 ml) was added palladium on carbon (250.00 mg). The solution was heated to 50° C. and stirred for 24 hours under a hydrogen atmosphere (15 psi). LCMS showed that the reaction of the starting material was complete and product was detected. The reaction solution was cooled to 20° C., filtered, and the filtrate was concentrated to give the title compound (Intermediate B) (600.00 mg, 2.10 mmol, 77.26% yield) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ ) δ8.55 (s, 1H), 8.20 (d, J = 3.9Hz, 1H), 7.96 (d, J = 9.2Hz, 1H), 7.69 (d, J = 9.7Hz, 1H), 5.06 (br s,2H),4.17(s,3H),3.54-3.45(m,1H),1.57(d,J=7.2Hz,6H).

Step 10:

5-(2-Chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-isopropyl-2-hydrogen-indazole

To a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-isopropenyl-2-hydrogen-indazole (Intermediate A) (36.50 g, 120.57 mmol, 1.00 equiv) in tetrahydrofuran (182.5 mL) was added Rh(PPh ₃ ) ₃ Cl (11.16 g, 12.06 mmol, 0.10 equiv). The reaction system was purged with hydrogen several times. The mixture was stirred at 50°C under a hydrogen pressure of 50 psi for 24 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25°C and concentrated under reduced pressure. Methanol (100 mL) was added to the residue and stirred for 16 hours. The mixture was then filtered and the filter cake was washed with methanol (15 mL x 3). The filter cake was then dried under reduced pressure to afford the title compound (Intermediate C) (28.00 g, 91.88 mmol, yield: 76.20%) as a slightly yellow solid. ¹ H NMR (400MHz, CDCl ₃ )8.69(s,1H),8.49(d,J＝3.5Hz,1H),8.06(d,J＝9.3Hz,1H),7.73(d,J＝9.3Hz,1H), 4.19(s,3H),3.58-3.49(m,1H),1.59(d,J=7.2Hz,6H).LCMS(ESI)m/z:305.2(M+1).

Example 1

N-(5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)-6-(4-methylpiperazin-1-yl)pyridazin-3-amine

Step 1:

6-(4-Methylpiperazin-1-yl)pyridazin-3-amine

6-Chloro-3-aminopyridazine (3.00 g, 23.16 mmol, 1.00 eq) and 1-methylpiperazine (8.10 g, 80.87 mmol, 3.49 eq) were added to a microwave tube and sealed. The mixture was heated to 170° C. under microwave stirring for 1.5 hours. LCMS showed that the reaction was complete. The mixture was cooled to 20° C. and concentrated under reduced pressure. The residue was purified by preparative HPLC (basic) to give the title compound (3.53 g, 18.27 mmol, 78.87% yield) as a white solid. ¹ H NMR (400MHz, DMSO-d ₆ )δ7.11(d,J＝9.6Hz,1H),6.73(d,J＝9.6Hz,1H),5.63(s,2H),3.30-3.24(m,4H),2.42-2.36(m,4H),2.19(s,3H).LCMS(ESI)m/z:194.1(M+1).

Step 2:

N-(5-Fluoro-4-(2-methyl-3-isopropenyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)-6-(4-methylpiperazin-1-yl)pyridazin-3-amine

Under nitrogen, to a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-isopropenyl-2hydro-indazole (Intermediate A) (350.00 mg, 1.16 mmol, 1.00 equiv) and 6-(4-methylpiperazin-1-yl)pyridazin-3-amine (228.65 mg, 1.18 mmol, 1.02 equiv) in dioxane (8 ml) were added Cs ₂ CO ₃ (753.39 mg, 2.31 μmol, 2.00 equiv), Xantphos (267.59 mg, 462.46 μmol, 0.40 equiv) and Pd ₂ (dba) ₃ (211.74 mg, 231.21 μmol, 0.20 equiv), and the mixture was stirred at 100-110° C. for 16 hours. TLC and LCMS showed complete reaction of the starting material. The mixture was cooled to 20°C and diluted with ethyl acetate (20 mL). Filtered, and the filtrate concentrated to yield the crude product. The crude product was added to methanol (10 mL) and allowed to stand at 25°C until a yellow precipitate formed. Filtered, the filter cake was washed with a small amount of methanol, and dried to yield the title compound (120.00 mg, 258.53 μmol, 22.29% yield, 99% purity) as a yellow solid. LCMS (ESI) m/z: 460.3 (M+1).

Step 3:

N-(5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)-6-(4-methylpiperazin-1-yl)pyridazin-3-amine

To a solution of Pd/C (50 mg) in methanol (10 mL) was added N-(5-fluoro-4-(2-methyl-3-isopropenyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)-6-(4-methylpiperazin-1-yl)pyridazin-3-amine (120.00 mg, 261.14 μmol, 1.00 equiv). Hydrogen was introduced into the reaction system while maintaining the pressure at 15 psi, and the mixture was stirred at 40-50° C. for 8 hours. LCMS showed that the reaction was complete, and the product was filtered, the filtrate was concentrated, and the residue was purified by preparative HPLC (hydrochloric acid) to give the title compound (57.00 mg, 123.50 μmol, 47.29% yield). ¹ H NMR (400MHz, methanol-d ₄ )δ8.72(s,1H),8.46(d,J＝4.0Hz,1H),8.41(d,J＝9.6Hz,1H),8.06(d,J＝9.2Hz,1H),7.65(d,J＝9.2Hz,1H),7.40(d,J＝9.2Hz, 1H), 4.20 (s, 3H), 3.68-3.61 (m, 5H), 2.63 (t, J = 4.8Hz, 4H), 2.39 (s, 3H), 1.59 (d, J = 7.2Hz, 6H). LCMS (ESI) m/z: 462.2 (M+1).

Example 2

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-N-(5-(piperazin-1-yl)pyrazin-2-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-(5-bromopyrazin-2-yl)piperazine-1-carboxylate

To a solution of 2,5-dibromopyrazine (10.00 g, 42.04 mmol, 1.00 equiv) in N-methylpyrrolidone (100 mL) were added tert-butyl piperazine-1-carboxylate (7.83 g, 42.04 mmol, 1.00 equiv) and _K₂CO₃ (8.72 _g , 63.06 mmol, 1.50 equiv). The mixture was heated to 100°C and stirred for 18 hours. TLC (petroleum ether:ethyl acetate = 10:1) indicated the reaction was complete. The mixture was cooled to 20°C and diluted with water (200 mL). The mixture was extracted with ethyl acetate (200 mL x 2), dried _over anhydrous _Na₂SO₄ , filtered, and concentrated. The residue was purified by column chromatography (petroleum ether:ethyl acetate = 20:1 to 5:1) to afford the title compound (11.00 g, 2.05 mmol, 76.24% yield) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ ) δ 8.15 (d, J = 1.38 Hz, 1H) 7.87 (d, J = 1.38 Hz, 1H) 3.56 (s, 8H) 1.49 (s, 9H).

Step 2:

tert-Butyl 4-(5-aminopyrazin-2-yl)piperazine-1-carboxylate

Under nitrogen, to a solution of tert-butyl 4-(5-bromopyrazin-2-yl)piperazine-1-carboxylate (10.00 g, 29.14 mmol, 1.00 equiv) and tri-tert-butylphosphine tetrafluoroborate (2.54 g, 8.74 mmol, 0.30 equiv) in toluene (100 mL) were added LHMDS (1 M, 60.00 mL, 2.06 equiv) and Pd ₂ (dba) ₃ (2.60 g, 2.84 mmol, 0.10 equiv), and the mixture was stirred at 65° C. for 16 hours. LCMS showed the reaction was complete, and the mixture was cooled to 20° C., quenched with water (50 mL), and extracted with ethyl acetate (100 mL×3). The organic phases were combined and concentrated, and the residue was dissolved in ethyl acetate (100 mL) and purified by preparative HPLC (basic) to afford the title compound (5.00 g, 17.90 mmol, 61.43% yield) as an orange solid. LCMS (ESI) m/z: 280.1 (M+1).

Step 3:

tert-Butyl 4-(5-((5-fluoro-4-(2-methyl-3-(isopropenyl)-2hydro-indazol-5-yl)pyrimidin-2-yl)amino)pyrazin-2-yl)piperazine-1-carboxylate

To a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-isopropenyl-2hydro-indazole (200.00 mg, 660.65 μmol, 1.00 equiv) and tert-butyl 4-(5-aminopyrazin-2-yl)piperazine-1-carboxylate (246.06 mg, 792.78 μmol, 1.20 equiv) in dioxane (10 ml) were added Cs ₂ CO ₃ (430.51 mg, 1.32 mmol, 2.00 equiv), Xantphos (152.91 mg, 264.26 μmol, 0.40 equiv) and Pd ₂ (dba) ₃ (120.99 mg, 132.13 μmol, 0.20 equiv) under nitrogen, and the mixture was stirred at 110-120° C. for 16 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25°C and filtered. The filter cake was washed with ethyl acetate, and the filtrate was concentrated. The residue was purified by preparative TLC (dichloromethane:methanol = 20:1) to afford the title compound (150.00 mg, 247.43 μmol, 37.45% yield, 90% purity) as a green solid. LCMS (ESI) m/z: 546.2 (M+1).

Step 4:

tert-Butyl 4-(5-((5-fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyrazin-2-yl)piperazine-1-carboxylate

To a solution of tert-butyl 4-(5-((5-fluoro-4-(2-methyl-3-(isopropenyl)-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyrazin-2-yl)piperazine-1-carboxylate (90.00 mg, 164.95 μmol, 1.00 equiv) in tetrahydrofuran (10 mL) were added palladium/carbon (100 mg) and a catalytic amount of acetic acid. Hydrogen was passed through the reaction system at a pressure of 15 psi, and the mixture was stirred at 50-60°C for 16 hours. LCMS indicated the reaction was complete. The mixture was cooled to 20°C, filtered, and the filtrate concentrated to afford the title compound (90.00 mg, crude product), which was used directly in the next reaction. LCMS (ESI) m/z: 548.3 (M+1).

Step 5:

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-N-(5-(piperazin-1-yl)pyrazin-2-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(5-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyrazin-2-yl)piperazine-1-carboxylate (90.00 mg, 164.34 μmol, 1.00 equiv) in methanol (5 mL) was added hydrochloric acid-methanol (4 M, 1 mL, 20 mmol, 1.00 equiv), and the mixture was stirred at 30-40° C. for 3 hours. TLC (dichloromethane:methanol = 30:1) showed complete consumption of the starting material, and LCMS showed 49% product and 44% by-product. The mixture was cooled to 25° C. and concentrated, and the residue was purified by preparative HPLC (hydrochloric acid) to give the title compound (6.00 mg, 13.41 μmol, 8.16% yield). ¹ H NMR (400MHz, methanol-d ₄ )δ8.96(s,1H),8.68(d,J＝4.4Hz,1H),8.31(d,J＝9.2Hz,1H),8.12(s,1H),7.79(d,J＝8.8Hz,1H),4.29(s,3H),3. 91(t,J＝4.8Hz,4H),3.74-3.69(m,1H),3.43(t,J＝5.2Hz,4H),1.65(d,J＝7.2Hz,6H).LCMS(ESI)m/z:448.1(M+1).

Example 3

5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-(6-nitropyridin-3-yl)piperazine-1-carboxylate

To a solution of 5-bromo-2-nitropyridine (20.00 g, 98.53 mmol, 1.00 equiv) in dimethyl sulfoxide (52 mL) were added tert-butyl piperazine-1-carboxylate (24.00 g, 128.86 mmol, 1.31 equiv) and triethylamine (20.00 g, 197.65 mmol, 2.01 equiv). The solution was heated to 60°C and stirred for 18 hours. TLC (petroleum ether:ethyl acetate = 3:1) indicated the reaction was complete. The solution was diluted with water (200 mL) and stirred for 30 minutes, then filtered. The filter cake was washed with water and dried under vacuum to obtain the crude product. The crude product was purified on a silica gel column (petroleum ether:ethyl acetate = 50:1 to 20:1) to obtain the title compound (27.00 g, 87.57 mmol, yield: 88.87%) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.18(d,J＝9.03Hz,1H),8.13(d,J＝2.89Hz,1H),7.21(dd,J＝9.10,2.95Hz,1H),3.69-3.59(m,4H),3.51-3.40(m,4H),1.49(s,9H).

Step 2:

tert-Butyl 4-(6-aminopyridin-3-yl)piperazine-1-carboxylate

Under nitrogen, palladium on carbon (6%, 1.7 g) was added to a solution of tert-butyl 4-(6-nitropyridin-3-yl)piperazine-1-carboxylate (28.00 g, 90.81 mmol, 1.00 equiv) in methanol (600 mL). The suspension was evacuated and filled with hydrogen several times. The solution was stirred at 50°C under a hydrogen atmosphere (50 psi) for 18 hours. TLC (dichloromethane:methanol = 10:1) indicated complete reaction of the starting material. The suspension was filtered, and the filtrate was dried to afford the title compound (24.13 g, 86.69 mmol, 95.46% yield) as a purple solid. ¹ H NMR (400MHz, CDCl ₃ ) δ7.78 (d, J = 2.64Hz, 1H) 7.18 (dd, J = 8.78, 2.89Hz, 1H) 6.50 (d, J = 8.78Hz, 1H) 4.21 (br s,2H)3.60-3.54(m,4H)3.00-2.92(m,4H)1.48(s,9H).

Step 3:

tert-Butyl 4-(6-((5-fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2hydro-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate

To a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-2-methyl-3-(prop-1-en-2-yl)-2-hydro-indazole (Intermediate A) (200.00 mg, 660.65 μmol, 1.00 equiv) in dioxane (10.00 mL) were added tert-butyl 4-(6-aminopyridin-3-yl)piperazine-1-carboxylate (220.67 mg, 792.79 μmol, 1.20 equiv), Pd ₂ (dba) ₃ (60.50 mg, 66.07 μmol, 0.10 equiv), Xantphos (76.45 mg, 132.13 μmol, 0.20 equiv), and cesium carbonate (430.51 mg, 1.32 mmol, 2.00 equiv). The solution was heated to 110° C. and stirred under nitrogen for 16 hours. LCMS indicated the reaction was complete. The solution was cooled to 25°C, filtered, and concentrated to yield the crude product. The crude product was purified by preparative TLC (ethyl acetate:petroleum ether = 1:2) to afford the title compound (320.00 mg, 587.57 μmol, 88.94% yield) as a pale yellow solid. LCMS (ESI) m/z: 545.3 (M+1).

Step 4:

tert-Butyl 4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate

Under nitrogen, to a solution of tert-butyl 4-(6-((5-fluoro-4-(2-methyl-3-(prop-1-en-2-yl)-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate in methanol (20.00 ml) were added palladium on carbon (200.00 mg) and acetic acid (2.10 g, 34.97 mmol, 59.52 equiv). The suspension was evacuated and filled with hydrogen several times. The solution was stirred at 50°C under a hydrogen atmosphere (32 psi) for 96 hours. LCMS indicated the reaction was complete. The suspension was cooled to 25°C, filtered, and concentrated to give the title compound (500.00 mg, crude product) as an off-white solid. LCMS (ESI) m/z: 547.1 (M+1).

Step 5:

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl(pyridin-2-yl)pyrimidin-2-amine)

To a solution of tert-butyl 4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate (500.00 mg, 914.68 μmol, 1.00 equiv) in dichloromethane (5.00 mL) at 25° C. was added trifluoroacetic acid (2.09 g, 18.29 mmol, 20.00 equiv) in one portion. The solution was stirred for 0.5 h. LCMS indicated the reaction was complete. The solution was concentrated under reduced pressure to afford the crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to afford the title compound (99.69 mg, 223.26 μmol, 24.41% yield). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.98(s,1H),8.85(d,J＝3.39Hz,1H),8.53(d,J＝9.03Hz,1H),8.32(dd,J＝ 9.72,2.20Hz,1H),8.01-7.96(m,1H),7.93(d,J＝9.03Hz,1H),7.60(d,J＝9. 66Hz,1H),4.39(s,3H),3.79(dt,J＝13.90,6.92Hz,1H),3.65-3.56(m,4H), 3.49(d,J＝5.02Hz,4H),1.69(d,J＝7.03Hz,6H).LCMS(ESI)m/z:447.1(M+1).

Example 4

Nitrogen-(5-(4-ethylpiperazin-1-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-(5-piperazin-1-yl-2-pyridinyl)pyrimidin-2-amine (210.00 mg, 470.30 μmol, 1.00 equiv) in methanol (5.00 mL) was added acetaldehyde (77.69 mg, 705.46 μmol, 1.50 equiv), _NaBH₃CN (59.11 mg, 940.61 μmol, 2.00 equiv), and acetic acid (14.12 mg, 235.15 μmol, 0.50 equiv). The solution was stirred at 20°C for 2 hours. LCMS indicated the reaction was complete. The solution was filtered, and the filtrate was concentrated under reduced pressure to provide the crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (66.50 mg, 128.83 μmol, yield: 27.39%, purity: 99%, hydrochloride). ¹ H NMR (400 MHz, Methanol-d ₄ )δ8.97(s,1H),8.84(d,J＝3.6Hz,1H),8.52(d,J＝9.2Hz,1H),8.32(dd,J＝9.7,2. 8Hz,1H),7.98(d,J＝2.8Hz,1H),7.92(d,J＝9.0Hz,1H),7.59(d,J＝9.5Hz,1H),4. 38(s,3H),4.02-3.93(m,2H),3.82-3.74(m,3H),3.38-3.34(m,4H),3.32-3.28( m, 2H), 1.69 (d, J = 7.0Hz, 6H), 1.46 (t, J = 7.3Hz, 3H). LCMS (ESI) m/z: 475.2 (M+1).

Example 5

Azo-(6-(1,4-diazepan-1-yl)pyridazin-3-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-(6-chloropyridazin-3-yl)-1,4-diazepane-1-carboxylate

To a solution of 3,6-dichloropyridazine (2.00 g, 13.42 mmol, 1.05 eq) and tert-butyl 1,4-diazoheptane-1-carboxylate (2.56 g, 12.78 mmol, 1.00 eq) in dimethyl sulfoxide (15.00 ml) was added triethylamine (3.88 g, 38.34 mmol, 3.00 eq) in one portion. The solution was heated to 80°C and stirred for 7 hours. LCMS indicated complete reaction of the starting material and MS of the product was detected. The solution was cooled to 25°C and concentrated to obtain the crude product. The crude product was purified by column chromatography (petroleum ether:ethyl acetate = 30:1 to 20:1) to obtain the title compound (1.20 g, crude product). The crude product was a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ7.18(d,J＝9.4Hz,1H),6.79(d,J＝9.4Hz,1H),3.87-3.57(m,6H),3.39-3.23(m,2H),1.99-1.93(m,2H),1.40(s,9H).LCMS(ESI)m/z:313.1(M+1).

Step 2:

tert-Butyl 4-(6-(5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-ylamino)pyridazin-3-yl)-1,4-diazepane-1-carboxylate

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine (Intermediate B) (200.00 mg, 700.97 μmol, 1.00 equiv) in dioxane (3.00 mL) were added tert-butyl 4-(6-chloropyridazin-3-yl)-1,4-diazepane-1-carboxylate, cesium carbonate (575.00 mg, 1.76 mmol, 2.52 equiv), _Pd2 (dba) ₃ (65.00 mg, 70.98 μmol, 0.10 equiv), and Xantphos (85.00 mg, 146.90 μmol, 0.21 equiv). The atmosphere in the vessel was replaced three times with nitrogen. The mixture was heated to 100°C and stirred for 18 hours. LCMS indicated complete reaction of the starting material and the product was detected. The solution was cooled to 20°C and concentrated to yield the crude product. The crude product was purified by preparative TLC (ethyl acetate) to afford the title compound (120.00 mg, 213.66 μmol, 30.48% yield) as a pale yellow solid. LCMS (ESI) m/z: 562.2 (M+1).

Step 3:

Azo-(6-(1,4-diazepan-1-yl)pyridazin-3-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(6-(5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-ylamino)pyridazin-3-yl)-1,4-diazepane-1-carboxylate (120.00 mg, 213.66 μmol, 1.00 equiv) in dichloromethane (2.00 mL) was added trifluoroacetic acid (1.00 mL) dropwise. The solution was stirred at 25° C. for 1 hour. LCMS showed that the reaction of the starting material was complete and product was detected. The solution was concentrated under reduced pressure to give the crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (45.38 mg, 98.32 μmol, yield: 46.02%). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.96(s,1H)8.85(d,J＝3.4Hz,1H)8.48(d,J＝9.2Hz,1H)8.08(d,J＝10.0Hz,1H)7.90(d,J＝9.2Hz,2H)4.36(s,3H)4 .11(t,J＝5.0Hz,2H)3.89(t,J＝5.9Hz,2H)3.76(quin,J＝7.0Hz,1H)3.52(t,J＝5.1Hz,2H)3.48-3.36(m,2H)2.28(br s,2H)1.68(d,J＝7.0Hz,6H).

Example 6

N-(6-(3-(dimethylamino)pyrrolidin-1-yl)pyridazin-3-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

Step 1:

1-(6-chloropyridazin-3-yl)-nitrogen, nitrogen-dimethylpyrrolidin-3-amine

A solution of 3,6-dichloropyridazine (1.20 g, 8.05 mmol, 1.00 equiv), N,N-dimethylpyrrolidin-3-amine (1.01 g, 8.86 mmol, 1.10 equiv), and triethylamine (815.06 mg, 8.05 mmol, 1.00 equiv) in N,N-dimethylformamide (15.00 ml) was heated to 80°C and stirred for 16 hours. LCMS indicated completion of the reaction and the product was detected. The solution was cooled to 25°C. The mixture was purified by preparative HPLC to afford the title compound (1.40 g, 6.18 mmol, 76.71% yield) as a light purple solid. LCMS (ESI) m/z: 227.1 (M+1).

Step 2:

N-(6-(3-(dimethylamino)pyrrol-1-yl)pyridazin-3-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine (Intermediate B) (150.00 mg, 525.73 μmol, 1.00 eq) in dioxane (3.00 mL) was added 1-(6-chloropyridazin-3-yl)-nitrogen, nitrogen-dimethyl-pyrrol-3-amine (143.03 mg, 630.88 μmol, 1.20 eq), cesium carbonate (428.23 mg, 1.31 mmol, 2.50 eq), Pd ₂ (dba) ₃ (48.14 mg, 52.57 μmol, 0.10 eq) and Xantphos (60.84 mg, 105.15 μmol, 0.20 eq). The atmosphere in the vessel was flushed with nitrogen three times. The mixture was heated to 100° C. and stirred for 18 hours. LCMS showed that some of the raw materials were unreacted and product was detected. The solution was cooled to 20°C and diluted with dichloromethane (10 ml), then filtered. The filtrate was concentrated to give a crude product, which was purified by preparative HPLC (hydrochloric acid) to give the title compound (15.33 mg, 32.24 μmol, yield: 6.13%). ¹ H NMR (400MHz, Methanol-d ₄ ) δ8.94 (s, 1H), 8.81 (d, J = 3.4Hz, 1H), 8.46 (d, J = 9.3Hz, 1H), 7.99 (br s,1H),7.92-7.78(m,2H),4.35(s,3H),4.26-4.09(m,2H),4.01-3.85(m,2H),3.84-3.64(m,2H),3.02(s,6H),2.66(br s,1H),2.46(dd,J＝7.9,13.1Hz,1H),1.67(d,J＝7.0Hz,6H).

Example 7

3-[4-[6-[[5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]propionitrile

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-N-(5-piperazin-1-yl-2-pyridyl)pyrimidin-2-amine (200.00 mg, 447.91 μmol, 1.00 equiv) in dimethyl sulfoxide (4 mL) was added potassium carbonate (123.81 mg, 895.82 μmol, 2.00 equiv) and 3-bromopropionitrile (120.01 mg, 895.82 μmol, 73.63 μL, 2.00 equiv). The mixture was stirred at 25°C for 16 hours. LCMS indicated the presence of approximately 50% starting material. The mixture was then heated to 50°C and stirred at 50°C for 2 hours. LCMS indicated the presence of approximately 16% starting material. Methanol (3 mL) was then added to the mixture. The mixture was stirred at 50°C for an additional 2 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25°C and concentrated to remove methanol to obtain a crude product. The crude product was diluted with water (15 mL) and filtered, and the filter cake was slurried with methanol (5 mL) to obtain the title compound (146.40 mg, 276.05 μmol, yield: 61.63%, purity: 94.2%). ¹ H NMR (400MHz, CDCl ₃ )δ8.68(s,1H),8.38-8.31(m,2H),8.07-8.02(m,2H),7.99(s,1H),7.73(d,J＝9.16Hz,1H),7.34(dd,J＝9.03,3.01Hz,1H),4.19(s,3H),3.57- 3.46(m,1H),3.22-3.14(m,4H),2.82-2.75(m,2H),2.74-2.67(m,4H),2.60-2.55(m,2H),1.59(d,J＝7.03Hz,6H).LCMS(ESI)m/z:500.3(M+1).

Example 8

2-[4-[6-[[5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]acetonitrile

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-(5-piperazin-1-yl-2-pyridyl)pyrimidin-2-amine (50.00 mg, 111.98 μmol, 1.00 equiv) in dimethyl sulfoxide (3 mL) was added potassium carbonate (30.95 mg, 223.96 μmol, 2.00 equiv) and bromoacetonitrile (26.86 mg, 223.96 μmol, 2.00 equiv). The mixture was stirred at 25°C for 1 hour. LCMS indicated the reaction was complete. The mixture was concentrated and then diluted with water (10 mL). The aqueous phase was extracted with ethyl acetate (10 mL x 3). The combined organic phases were washed with saturated brine (15 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to give the crude product. The crude product was purified by slurrying with methanol (5 mL x 2) to give the title compound (12.40 mg, 24.52 μmol, yield: 21.89%, purity: 96%). ¹ H NMR (300MHz, DMSO-d ₆ )δ9.70(s,1H),8.67(s,1H),8.58(d,J＝3.96Hz,1H),8.14-8.00(m,2H),7.9 2(d,J＝9.23Hz,1H),7.66(d,J＝9.23Hz,1H),7.43(dd,J＝9.04Hz,3.01Hz,1H ),4.14(s,3H),3.81(s,2H),3.60(td,J＝13.85,6.83Hz,1H),3.22-3.11(m, 4H), 2.69-2.60 (m, 4H), 1.50 (d, J＝6.97Hz, 6H). LCMS (ESI) m/z: 486.3 (M+1).

Example 9

N-[5-[4-(2-aminoethyl)piperazin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Step 1:

2-(4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-1-yl)acetonitrile

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-(5-piperazin-1-yl-2-pyridyl)pyrimidin-2-amine (17.60 g, 39.42 mmol, 1.00 equiv) and potassium carbonate (10.90 g, 78.84 mmol, 2.00 equiv) in dimethyl sulfoxide (176.00 mL) was added 2-bromoacetonitrile (9.46 g, 78.84 mmol, 5.26 mL, 2.00 equiv). The mixture was stirred at 30° C. for 1 hour. LC-MS showed the reaction was complete. The mixture was poured into water (30 mL) and filtered. The resulting filter cake was washed with water (5 mL x 2) and dried in vacuo to afford the title compound (16.00 g, 32.95 mmol, 83.59% yield) as a yellow solid. LCMS (ESI) m/z: 486.3 (M+1).

Step 2:

N-[5-[4-(2-aminoethyl)piperazin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Under a hydrogen pressure of 50 psi, a mixed solution of 2-(4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-1-yl)acetonitrile (6.00 g, 12.36 mmol, 1.00 eq) and radium nickel (8.47 g, 98.88 mmol, 8.00 eq) in aqueous ammonia (10.00 ml) and tetrahydrofuran (100.00 ml) was stirred at 50° C. for 16 hours. LC-MS showed that the reaction was complete. The mixture was filtered. The resulting filter cake was washed with ethanol (100 ml×3). The combined organic layers were concentrated in vacuo to give a crude product, and the residue was purified by preparative HPLC (hydrochloric acid) to give the title compound (6.50 g, 10.85 mmol, yield: 87.80%, purity: 100%, hydrochloride salt). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.90(s,1H),8.79(d,J＝3.6Hz,1H),8.39-8.22(m,2H),7.95(d,J＝2.9Hz,1H),7.82(d,J＝9.2Hz,1H),7.58(d,J＝9.7Hz,1H),4.30(s,3H) ,3.73(td,J＝14.0,7.1Hz,3H),3.68-3.54(m,6H),3.50(br.s.,2H),3.34(br.s.,2H),1.65(d,J＝7.0Hz,6H).LCMS(ESI)m/z:490.3(M+1).

Example 10

2-[4-[6-[[5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]ethanol

Step 1:

2-[4-[6-[[5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]ethanol

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-(5-piperazin-1-yl-2-pyridyl)pyrimidin-2-amine (2.00 g, 4.48 mmol, 1.00 equiv) and 2-bromoethanol (1.68 g, 13.44 mmol, 954.55 μL, 3.00 equiv) in ethanol (30.00 mL) was added diisopropylethylamine (1.74 g, 13.44 mmol, 2.35 mL, 3.00 equiv). The mixture was heated to 80° C. and stirred for 16 hours. LC-MS indicated that the starting material was almost completely consumed and the MS of the desired compound was detected. The mixture was cooled to 25° C. and filtered. The filter cake was slurried with methanol (10 ml), the compound was filtered, and the filter cake was dried to give the title compound (1.50 g, 2.97 mmol, yield: 66.20%, purity: 97%). ¹ H NMR (400 MHz, Methanol-d ₄ ) δ 8.74 (s, 1H), 8.44 (d, J = 3.9 Hz, 1H), 8.23 (d, J = 9.0 Hz, 1H), 8.07 (d, J = 8.9 Hz, 1H), 8.01 (d, J = 2.6 Hz, 1H), 7.65 (d, J = 9.2 Hz, 1H), 7.49 (dd, J = 9.0, 2.9 Hz, 1H), 4.19 (s, 3 H),3.75(t,J＝6.0Hz,2H),3.64(td,J＝14.1,7.0Hz,1H),3.26-3.18(m,4H),2.80-2. 70(m,4H),2.62(t,J＝6.0Hz,2H),1.60(d,J＝7.0Hz,6H).LCMS(ESI)m/z:491.3(M+1).

Example 11

(4-(6-((5-Fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-2-yl)methanol

Step 1:

Piperazine-2-ylmethanol

To a suspension of lithium aluminum tetrahydride (5.61 g, 147.74 mmol, 1.5 eq) in tetrahydrofuran (300 mL) at 0°C was added piperazine-2-carboxylic acid (20.00 g, 98.49 mmol, 1.00 eq, dihydrochloride) in portions. The mixture was heated to 70°C and stirred for 18 hours. LCMS showed complete conversion of the starting material and the detection of the desired product. The reaction mixture was cooled to 0°C and quenched with water (5 mL) and aqueous sodium hydroxide solution (15%, 5 mL). The mixture was filtered, the filter cake was washed with dichloromethane (100 mL), and the filtrate was dried over anhydrous sodium sulfate and concentrated to afford the title compound (2.4 g, 20.66 mmol, yield: 20.98%) as a light yellow oil. ¹ H NMR (400MHz, CDCl ₃ )δ3.54(dd,J＝4.1,10.7Hz,1H),3.40(d,J＝7.2Hz,1H),3.02-2.95(m,1H),2.90(dd ,J＝11.9,2.6Hz,3H),2.81-2.75(m,4H),2.47(dd,J＝11.8,10.3Hz,1H),1.41(s,1H)

Step 2:

(4-(6-Nitropyridin-3-yl)piperazin-2-yl)methanol

To a solution of piperazin-2-ylmethanol (2.4 g, 20.66 mmol, 1.00 equiv) in dimethyl sulfoxide (20.00 mL) was added 5-bromo-2-nitropyridine (4.19 g, 20.66 mmol, 1.00 equiv) and triethylamine (4.18 g, 41.32 mmol, 2.00 equiv). The reaction mixture was heated to 50°C and stirred for 18 hours. LCMS showed complete conversion of the starting material and the desired product was detected. The reaction mixture was used directly in the next step. LCMS (ESI) m/z: 293.1 (M ⁺ 1).

Step 3:

tert-Butyl 2-(((tert-Butoxycarbonyl)oxy)methyl)-4-(6-nitropyridin-3-yl)piperazine-1-carboxylate

To a solution of (4-(6-nitropyridin-3-yl)piperazin-2-yl)methanol (4.92 g, 20.65 mmol, 1.00 equiv) in dichloromethane (40.00 mL) were added triethylamine (6.27 g, 61.95 mmol, 3.00 equiv) and di-tert-butyl dicarbonate (9.01 g, 41.3 mmol, 2.00 equiv). The mixture was stirred at 15°C for 18 hours. TLC (petroleum ether:ethyl acetate = 1:1) indicated complete conversion of the starting material. The reaction mixture was diluted with water (100 mL) and the dichloromethane was removed under vacuum. The aqueous phase was extracted with ethyl acetate (50 mL x 3). The combined organic phases were washed sequentially with water (50 mL) and saturated brine (30 mL), dried over anhydrous sodium sulfate, and concentrated to yield a residue. The residue was purified by column chromatography (petroleum ether:ethyl acetate = 10:1 to 3:1) to give the title compound (1.5 g, 3.42 mmol, yield: 16.57%) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.18(d,J＝9.03Hz,1H)8.11(d,J＝3.01Hz,1H)7.20(dd,J＝9.16,3.14Hz,1H)4.46(br.s.,1H)4.12-4.25(m,2H)4. 02(br.s.,1H)3.93(d,J＝13.30Hz,1H)3.70-3.80(m,1H)3.28-3.43(m,2H)3.14-3.25(m,1H)1.50(s,9H)1.46(s,9H)

Step 4:

tert-Butyl 4-(6-amino-3-pyridyl)-2-(tert-butoxycarbonyloxymethyl)piperazine-1-carboxylate

To a solution of tert-butyl 2-(((tert-butoxycarbonyl)oxy)methyl)-4-(6-nitropyridin-3-yl)piperazine-1-carboxylate (500 mg, 1.14 mmol, 1.00 equiv) in methanol (30.00 mL) was added wet palladium on carbon (200.00 mg). The reaction flask was purged with argon and hydrogen three times. The mixture was stirred at 15°C under a hydrogen pressure (15 psi) for 18 hours. TLC (petroleum ether:ethyl acetate = 1:1) indicated complete conversion of the starting material. The reaction mixture was filtered, and the filter cake was washed with methanol (10 mL). The filtrate was concentrated to give a residue, which was purified by preparative TLC (ethyl acetate) to afford the title compound (200.00 mg, 489.61 μmol, yield: 42.95%) as a brown solid. LCMS (ESI) m/z: 409.2 (M+1).

Step 5:

tert-Butyl 2-(((tert-Butoxycarbonyl)oxy)methyl)-4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2hydro-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate

Under nitrogen protection, to a solution of tert-butyl 4-(6-amino-3-pyridyl)-2-(tert-butoxycarbonyloxymethyl)piperazine-1-carboxylate (200.00 mg, 489.61 μmol, 1.00 equiv) in dioxane (5 mL) were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (Intermediate C) (150.70 mg, 494.51 μmol, 1.01 equiv), cesium carbonate (319.05 mg, 979.22 μmol, 2.00 equiv), Pd ₂ (dba) ₃ (44.83 mg, 48.96 μmol, 0.10 equiv) and Xantphos (56.66 mg, 97.92 μmol, 0.20 equiv). The reaction flask was purged with nitrogen three times. The mixture was heated to 100°C and stirred for 18 hours. LCMS showed complete conversion of the starting material and detection of the desired product. The reaction mixture was cooled to 15°C and filtered, and the filter cake was washed with ethyl acetate (5 mL). The filtrate was concentrated to obtain a residue which was purified by preparative TLC (petroleum ether:ethyl acetate = 1:1) to afford the title compound (104.00 mg, 153.67 μmol, yield: 31.39%) as a brown solid. ¹ H NMR (300 MHz, CDCl ₃ )δ8.69(s,1H),8.37(d,J＝4.0Hz,1H),8.07-7.98(m,2H),7.73(d,J＝9.2Hz,1 H),7.35(dd,J＝2.9,9.1Hz,1H),4.49(br.s.,1H),4.46-4.25(m,2H),4.19(s, 3H),4.03(br.s.,1H),3.57-3.50(m,2H),3.39(d,J＝11.5Hz,1H),3.23(t,J＝9 .6Hz,1H),2.94-2.69(m,2H),1.60(d,J＝7.0Hz,6H),1.50(s,9H),1.50(s,9H)

Step 6:

(4-(6-((5-Fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-2-yl)methanol

To a solution of tert-butyl 2-(((tert-butoxycarbonyl)oxy)methyl)-4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate (100 mg, 147.76 μmol, 1.00 equiv) in dichloromethane (2.00 mL) was added trifluoroacetic acid (1.00 mL). The mixture was stirred at 15°C for 1 hour. LCMS indicated complete conversion of the starting material and detection of the desired product. The reaction mixture was concentrated to obtain a residue which was purified by preparative HPLC (hydrochloric acid) to yield the desired compound (43.08 mg, 78.41 μmol, yield: 53.07%, hydrochloride salt). ¹ H NMR (400 MHz, methanol-d ₄ )δ8.92(s,1H),8.80(d,J＝3.5Hz,1H),8.41(d,J＝9.2Hz,1H),8.30(dd,J＝2.5,9.7H z,1H),7.96(d,J＝2.5Hz,1H),7.85(d,J＝9.0Hz,1H),7.57(d,J＝9.5Hz,1H),4.33(s ,3H),3.96-3.84(m,3H),3.84-3.69(m,2H),3.57(d,J＝12.9Hz,2H),3.39(dt,J＝3. 0,12.1Hz,1H),3.28-3.09(m,2H),1.65(d,J＝7.0Hz,6H)LCMS(ESI)m/z:477.2(M+1)

Example 12

N-[5-[3-(ethylamino)pyrrolidin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Step 1:

tert-Butyl (3S)-3-hydroxypyrrolidine-1-carboxylate

To a solution of (3S)-pyrrolidin-3-ol (3.50 g, 28.32 mmol, 1.00 equiv, hydrochloride) in dichloromethane (30.00 mL) were added triethylamine (11.46 g, 113.28 mmol, 4.00 equiv) and di-tert-butyl dicarbonate (8.04 g, 36.82 mmol, 1.30 equiv). The mixture was stirred at 20°C for 18 hours. TLC indicated the reaction was complete. The mixture was diluted with water (10 mL), followed by the addition of 10% aqueous citric acid (20 mL). The aqueous phase was extracted with dichloromethane (10 mL x 2), and the combined organic phases were washed with saturated brine (20 mL x 1), dried over anhydrous sodium sulfate, filtered, and concentrated to afford the title compound (4.00 g, crude) as a yellow oil. ¹ H NMR (400MHz, Methanol-d ₄ ) δ4.42-4.32(m,1H), 3.49-3.35(m,3H), 3.31-3.19(m,1H), 2.08-1.82(m,2H), 1.51-1.42(m,9H).

Step 2:

tert-Butyl 3-oxopyrrolidine-1-carboxylate

To a solution of tert-butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (500.00 mg, 2.67 mmol, 1.00 equiv) in dichloromethane (10.00 mL) at 0°C was added Dess-Martin reagent (1.70 g, 4.01 mmol, 1.50 equiv) portionwise. The mixture was warmed to 20°C and stirred at 20°C for 18 hours. TLC indicated the reaction was complete. The reaction solution was quenched with 10 mL of 30% sodium sulfite solution and sodium bicarbonate (5 mL) solution was added. The aqueous phase was extracted with dichloromethane (5 mL x 3). The combined organic phases were washed with saturated brine (15 mL x 1), dried over anhydrous sodium sulfate, filtered, and concentrated to afford the title compound (453.00 mg, crude product) as a yellow oil. ¹ H NMR (400MHz, CDCl ₃ ) δ3.85-3.65(m,4H), 2.66-2.52(m,2H), 1.51-1.44(m,9H).

Step 3:

tert-Butyl 3-[Benzyl(ethyl)amino]pyrrolidine-1-carboxylate

To a solution of tert-butyl 3-oxopyrrolidine-1-carboxylate (353.00 mg, 1.91 mmol, 1.00 equiv) in dichloromethane (8.00 ml) at 0°C were added benzylethylamine (309.90 mg, 2.29 mmol, 1.20 equiv) and acetic acid (1.15 mg, 19.10 μmol, 0.01 equiv). The mixture was stirred at 0°C for 0.5 h. Sodium cyanoborohydride (647.69 mg, 3.06 mmol, 1.60 equiv) was then added. The mixture was stirred at 25°C for 3 h. LCMS showed that the reaction was complete. The mixture was quenched with water (10 ml). The aqueous phase was extracted with dichloromethane (10 ml x 2). The combined organic phases were washed with saturated brine (10 ml x 1), dried over anhydrous sodium sulfate, filtered, and concentrated to give the crude product. The crude product was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 20:1 to 10:1) to give the title compound (211.00 mg, 693.10 μmol, yield: 36.29%) as a colorless oil. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.38-7.28 (m, 4H), 7.25 (d, J = 6.27 Hz, 1H), 3.71-3.06 (m, 7H), 2.59 (q, J = 7.15 Hz, 2H), 2.06-1.98 (m, 1H), 1.90-1.77 (m, 1H), 1.46 (s, 9H), 1.04-0.97 (m, 3H). LCMS (ESI) m/z: 305.3 (M+1).

Step 4:

N-Benzyl-N-ethyl-pyrrolidin-3-amine

To a solution of tert-butyl 3-[benzyl(ethyl)amino]pyrrolidine-1-carboxylate (2.00 g, 6.57 mmol, 1.00 equiv) in dichloromethane (12 mL) was added trifluoroacetic acid (4.59 g, 40.27 mmol, 6.13 equiv). The mixture was stirred at 20°C for 30 minutes. TLC indicated the reaction was complete. The reaction solution was concentrated to afford the title compound (2.00 g, crude, trifluoroacetate salt) as a yellow oil. LCMS (ESI) m/z: 205.3 (M+1).

Step 5:

N-benzyl-N-ethyl-1-(6-nitro-3-pyridyl)pyrrolidin-3-amine

To a solution of N-benzyl-N-ethyl-pyrrolidin-3-amine (2.00 g, 4.63 mmol, 1.00 equiv, trifluoroacetate) in dimethyl sulfoxide (10.00 mL) were added triethylamine (2.74 g, 27.06 mmol, 5.85 equiv) and 5-bromo-2-nitropyridine (1.13 g, 5.55 mmol, 1.20 equiv). The mixture was stirred at 90°C for 18 hours. LCMS indicated the reaction was complete. The mixture was diluted with water (20 mL), and the aqueous phase was extracted with ethyl acetate (15 mL x 4). The combined organic phases were washed with saturated brine (20 mL x 1), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1 to 3:1) to yield the title compound (700.00 mg, crude) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.16(d,J＝9.04Hz,1H),7.77(d,J＝3.01Hz,1H),7.41-7.28(m,4H),6.81(dd,J＝9.14,2.92Hz,1H),3.85-3 .25(m,8H),2.68(q,J＝7.03Hz,2H),2.36-1.97(m,2H),1.09(t,J＝7.06Hz,3H).LCMS(ESI)m/z:327.2(M+1).

Step 6:

5-[3-[Benzyl(ethyl)amino]pyrrolidin-1-yl]pyridin-2-amine

To a solution of N-benzyl-N-ethyl-1-(6-nitro-3-pyridyl)pyrrolidin-3-amine (450.00 mg, 1.38 mmol, 1.00 equiv) in ethanol (10 mL) were added zinc powder (360.62 mg, 5.52 mmol, 4.00 equiv) and ammonium chloride (737.48 mg, 13.80 mmol, 10.00 equiv). The mixture was heated to 70°C and stirred for 3 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25°C, filtered, and the filtrate concentrated to afford the title compound (216.00 mg, crude) as a purple solid. LCMS (ESI) m/z: 297.2 (M+1).

Step 7:

N-[5-[3-[benzyl(ethyl)amino]pyrrolidin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Under nitrogen, to a solution of 5-[3-[benzyl(ethyl)amino]pyrrolidin-1-yl]pyridin-2-amine (129.00 mg, 435.21 μmol, 1.00 eq) in dioxane (4.00 mL) were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (Intermediate C) (159.16 mg, 522.25 μmol, 1.20 eq), Pd ₂ (dba) ₃ (39.85 mg, 43.52 μmol, 0.10 eq), Xantphos (50.36 mg, 87.04 μmol, 0.20 eq), and cesium carbonate (354.50 mg, 1.09 mmol, 2.50 eq). The mixture was stirred at 110° C. for 18 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25°C and then concentrated to give the crude product. The crude product was purified by preparative TLC (ethyl acetate) to give the title compound (145.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 565.3 (M+1). Step 8:

N-[5-[3-(ethylamino)pyrrolidin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

To a solution of N-[5-[3-[benzyl(ethyl)amino]pyrrolidin-1-yl]-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine (181.00 mg, 320.52 μmol, 1.00 equiv) in tetrahydrofuran (5 mL) was added wet palladium on carbon (400.00 mg) and ammonium formate (2.02 g, 32.05 mmol, 100.00 equiv). The mixture was stirred at 60° C. for 16 hours. LCMS indicated the reaction was complete. The mixture was cooled to 25° C. and then filtered. The filtrate was concentrated to give the crude product, which was purified by preparative HPLC (hydrochloric acid) to give the title compound (34.64 mg, 59.47 μmol, 18.56% yield, 94% purity, hydrochloride). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.89(s,1H),8.75(d,J＝3.64Hz,1H),8.35(d,J＝9.29Hz,1H),7.92(dd,J＝9.60,2.95Hz,1H) ,7.81(d,J＝9.16Hz,1H),7.64(d,J＝2.89Hz,1H),7.53(d,J＝9.54Hz,1H),4.30(s,3H),4.18-4. 02(m,1H),3.61-3.85(m,4H),3.54-3.41(m,1H),3.23(q,J＝7.24Hz,2H),2.69-2.52(m,1H),2 .44-2.27(m,1H),1.65(d,J＝7.03Hz,6H),1.40(t,J＝7.28Hz,3H).LCMS(ESI)m/z:475.3(M+1).

Example 13

5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-[5-(piperidin-4-yl)-2-pyridinyl]pyrimidin-2-amine

Step 1:

tert-Butyl 4-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperidine-1-carboxylate

To a solution of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (1.00 g, 3.28 mmol, 1.00 equiv) in dioxane (10 mL) was added tert-butyl 4-(6-amino-3-pyridyl)piperidine-1-carboxylate (1.09 g, 3.94 mmol, 1.20 equiv), _Pd2 (dba) ₃ (150.18 mg, 164.00 μmol, 0.05 equiv), Xantphos (189.79 mg, 328.00 μmol, 0.10 equiv), and cesium carbonate (2.14 g, 6.56 μmol, 2.00 equiv) under nitrogen. The mixture was stirred at 110°C for 16 hours. LCMS indicated the reaction was complete. The mixture was concentrated to give the crude product. The crude product was diluted with dichloromethane (10 mL) and filtered. The filtrate was concentrated to yield the crude product. This crude product was purified by slurrying with methanol (10 mL) to afford the title compound (1.11 g, crude). LCMS (ESI) m/z: 546.2 (M+1).

Step 2:

5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-N-[5-(piperidin-4-yl)-2-pyridinyl]pyrimidin-2-amine

To a solution of tert-butyl 4-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperidine-1-carboxylate (1.08 g, 1.98 mmol, 1.00 equiv) in dichloromethane (12 mL) was added trifluoroacetic acid (5.36 g, 46.97 mmol, 3.48 mL, 23.72 equiv). The mixture was stirred at 25°C for 1 hour. LCMS indicated the reaction was complete. The mixture was concentrated to give the crude product. 0.7 g of the crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (183.40 mg, 350.38 μmol, 17.70% yield, 99.05% purity) as a yellow solid. ¹ H NMR (400MHz, Methanol-d ₄ )δ8.93(s,1H),8.83(d,J＝3.51Hz,1H),8.32-8.45(m,3H),7.85(d,J＝9.03Hz,1H),7.62(d,J＝9.16Hz,1H),4.33(s,3H),3.74(d,J＝6.99Hz,1H) ,3.57(d,J＝12.67Hz,2H),3.10-3.27(m,3H),2.20(d,J＝13.68Hz,2H),1.96-2.10(m,2H),1.66(d,J＝7.03Hz,6H).LCMS(ESI)m/z:446.2(M+1).

Example 14

3-[4-[6-[[5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]-1-piperidinyl]propionitrile

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitro-[5-(4-piperidinyl)-2-pyridinyl]pyrimidin-2-amine (1.25 g, 1.86 mmol, 1.00 equiv, trifluoroacetate) in methanol (10 mL) was added triethylamine (1.10 g, 10.82 mmol, 1.50 mL, 5.82 equiv). The mixture was stirred at 25°C for 30 minutes, followed by the addition of potassium carbonate (514.14 mg, 3.72 mmol, 2.00 equiv) and 3-bromopropionitrile (498.37 mg, 3.72 mmol, 305.75 μL, 2.00 equiv). The mixture was stirred at 25°C for 16 hours. LCMS indicated the reaction was complete. The mixture was concentrated, diluted with water (15 mL), and filtered to obtain a filter cake. The filter cake was slurried with methanol (8 mL) to give the title compound (217.00 mg, 412.59 μmol, yield: 22.18%, purity: 94.8%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.70 (s, 1H), 8.42-8.36 (m, 2H), 8.19 (d, J = 2.13 Hz, 1H), 8.02-8.09 (m, 2H), 7.74 (d, J = 9.16 Hz, 1H), 7.58 (dd, J = 8.66 Hz, 2.38 Hz, 1H), 4.19 (s, 3H), 3.59-3.45 (m, 1H),3.04(d,J＝11.29Hz,2H),2.91-2.73(m,2H),2.60-2.47(m,3H),2.23(dt,J＝1 1.48Hz,2.51Hz,2H),1.93-1.72(m,4H),1.59(s,6H).LCMS(ESI)m/z:499.3(M+1).

Example 15

Azo-(5-((1S,4S)-2,5-diazabicyclo[2.2.1]heptane-2-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 5-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)-(1S,4S)-2,5-diazabicyclo[2.2.1]heptane-2-carboxylate

Under nitrogen protection, 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (Intermediate C) (376.67 mg, 1.24 mmol, 1.20 equiv), 5-(6-amino-3-pyridyl)-(1S,4S)-2,5-diazabicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester (300.00 mg, 1.03 mmol, 1.00 equiv), cesium carbonate (671.19 mg, 2.06 mmol, 2.00 equiv), Pd(OAc) ₂ A solution of hydroxybenzoic acid (46.25 mg, 206.00 μmol, 0.20 equiv) and XPhos (196.41 mg, 412.00 μmol, 0.40 equiv) in dioxane (10.00 mL) was replaced with nitrogen three times, and the mixture was stirred at 100°C for 16 hours. LCMS indicated the reaction was complete. The mixture was concentrated under reduced pressure to a residue, which was purified by preparative TLC (petroleum ether:ethyl acetate = 1:2) to give the title compound (350.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 559.3 (M+1).

Step 2:

Azo-(5-((1S,4S)-2,5-diazabicyclo[2.2.1]heptane-2-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

To a solution of tert-butyl 5-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)-(1S,4S)-2,5-diazabicyclo[2.2.1]heptane-2-carboxylate (365.00 mg, 653.36 μmol, 1.00 equiv) in dichloromethane (8.00 mL) was added trifluoroacetic acid (4.00 mL) dropwise over 15 minutes at 0°C, and the reaction mixture was allowed to react at 15°C for 80 minutes. LCMS indicated the reaction was complete. The mixture was concentrated under reduced pressure to a residue, which was then purified by preparative HPLC (hydrochloric acid) to give the title compound (110.00 mg, 239.90 μmol, yield: 36.72%, purity: 100%). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.92(s,1H),8.78(d,J＝3.51Hz,1H),8.43(d,J＝9.29Hz,1H),7.98(dd,J＝9.66,2.89Hz,1H),7.88 -7.83(m,1H),7.72(d,J＝2.89Hz,1H),7.54(d,J＝9.54Hz,1H),4.83(s,1H),4.62(s,1H),4.34(s,3H) ,3.80(dd,J＝10.60,2.32Hz,1H),3.77-3.70(m,1H),3.55(d,J＝10.54Hz,1H),3.50-3.41(m,2H),2. 36(d,J＝11.29Hz,1H),2.17(d,J＝11.42Hz,1H),1.66(d,J＝7.03Hz,6H).LCMS(ESI)m/z:459.3(M+1).

Example 16

Azo-(5-(1,7-diazaspiro[4.4]nonan-7-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

Step 1:

(S)-1-Benzoylproline methyl ester

To a solution of L-proline methyl ester hydrochloride (20.00 g, 120.76 mmol, 1.00 equiv) in dichloromethane (300.00 mL) were added triethylamine (36.66 g, 362.28 mmol, 3.00 equiv) and benzoyl chloride (16.98 g, 120.76 mmol, 1.00 equiv). The reaction mixture was stirred at 15°C for 18 hours. LCMS indicated complete conversion of the starting material and detection of the desired product. The reaction mixture was concentrated to obtain a residue which was diluted with ethyl acetate (200 mL) and washed sequentially with water (100 mL), aqueous citric acid (2.5%, 100 mL), and saturated sodium bicarbonate (100 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated to afford the title compound (24.00 g, 102.89 mmol, yield: 85.20%) as a white solid. ¹ H NMR (400MHz, CDCl ₃ )δ7.63-7.52(m,2H),7.45-7.38(m,3H),4.68(dd,J＝5.2,8.2Hz,1H),3.82-3.75(m,3H),3.66(td ,J＝7.0,10.2Hz,1H),3.57-3.53(m,1H),2.40-2.17(m,1H),2.07-1.98(m,2H),1.95-1.82(m,1H)

Step 2:

Methyl 1-benzoyl-2-(nitrilemethyl)pyrrolidine-2-carboxylate

To a solution of (S)-1-benzoylpyrrolidine-2-carboxylic acid methyl ester (10.00 g, 42.87 mmol, 1.00 equiv) in tetrahydrofuran (150.00 mL) was added dropwise a solution of lithium diisopropylamine in tetrahydrofuran (2 mol/L, 25.72 mL, 1.20 equiv) at -78°C, and the mixture was stirred for 1 hour. A solution of 2-bromoacetonitrile (6.17 g, 51.44 mmol, 1.20 equiv) in tetrahydrofuran (30.00 mL) was then added dropwise. The mixture was stirred at 15°C for 18 hours. LCMS indicated complete conversion of the starting material and detection of the desired product. The reaction mixture was quenched with saturated aqueous ammonium chloride (100 mL) and the layers separated. The aqueous phase was extracted with ethyl acetate (100 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated to afford the title compound (12.00 g, crude) as a brown oil. This crude product was used directly in the next step. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.60-7.54 (m, 2H), 7.50-7.40 (m, 3H), 3.81 (s, 3H), 3.80-3.77 (m, 1H), 3.77-3.73 (m, 1H), 3.71-3.64 (m, 1H), 3.15 (d, J = 17.2 Hz, 1H), 2.44-2.27 (m, 2H), 2.17-2.05 (m, 2H)

Step 3:

1-Benzoyl-1,7-diazaspiro[4,4]nonan-6-one

To a solution of methyl 1-benzoyl-2-(nitrilemethyl)pyrrolidine-2-carboxylate (5.00 g, 18.36 mmol, 1.00 equiv) and aqueous ammonia (5.00 ml) in methanol (100.00 ml) was added Raney nickel (5.00 g). The reaction flask was purged three times with argon and then hydrogen. The mixture was heated to 70°C under a hydrogen pressure of 55 psi and stirred for 18 hours. LCMS showed complete conversion of the starting material and the detection of the desired product. The reaction mixture was cooled to 25°C and filtered. The residue obtained by concentration of the filtrate was purified on a silica gel column (petroleum ether:ethyl acetate = 3:1 to dichloromethane:methanol = 30:1) to afford the title compound (2.25 g, yield: 50.17%) as a light brown solid. ¹ H NMR (400MHz, CDCl ₃ )δ7.62-7.50(m,2H),7.45-7.35(m,3H),5.84(br.s.,1H),3.71-3.53(m,3H),3.42-3.34(m,1H),2. 95(ddd,J＝12.8,9.7,6.8Hz,1H),2.34(td,J＝6.7,12.5Hz,1H),2.20-1.96(m,3H),1.94-1.82(m,1H)

Step 4:

1-Benzyl-1,7-diazaspiro[4,4]nonane

To a suspension of lithium aluminum tetrahydride (7.13 g, 187.99 mmol, 5.60 equiv) in tetrahydrofuran (300.00 mL) at 0°C was added 1-benzoyl-1,7-diazaspiro[4,4]nonan-6-one (8.2 g, 33.57 mmol, 1.00 equiv) portionwise. After the addition was complete, the mixture was heated to 70°C and stirred for 2 hours. LCMS indicated complete conversion of the starting material and the detection of the desired product. The reaction mixture was cooled to 15°C and quenched with water (7 mL). Aqueous sodium hydroxide (15%, 7 mL) and water (21 mL) were then added. The mixture was filtered, and the filtrate was dried over anhydrous sodium sulfate. The resulting residue was concentrated and passed through a silica gel column (dichloromethane:methanol = 30:1 to 10:1) to afford the title compound (3.67 g, 16.97 mmol, yield: 50.54%) as a pale yellow oil. ¹ H NMR (400 MHz, CDCl ₃ )δ7.36-7.28(m,4H),7.26-7.20(m,1H),3.69(d,J＝13.2Hz,1H),3.59(d,J＝ 13.2Hz,1H),3.13-3.04(m,2H),2.99(td,J＝10.8,7.7Hz,1H),2.77(d,J＝11 .2Hz,1H),2.70-2.62(m,1H),2.59-2.51(m,1H),2.01(td,J＝12.9,8.1Hz,2 H),1.92-1.85(m,2H),1.80-1.71(m,2H),1.59(ddd,J＝12.6,7.6,4.6Hz,1H)

Step 5:

1-Benzyl-7-(6-nitropyridin-3-yl)-1,7-diazaspiro[4,4]nonane

To a solution of 1-benzyl-1,7-diazaspiro[4,4]nonane (1.80 g, 8.32 mmol, 1.00 equiv) and 5-bromo-2-nitropyridine (1.81 g, 8.90 mmol, 1.07 equiv) in nitrogen-dimethylformamide (20.00 ml) was added triethylamine (1.80 g, 17.80 mmol, 2.14 equiv). The mixture was heated to 100°C and stirred for 18 hours. LCMS showed complete conversion of the starting material and the detection of the desired product. The reaction mixture was cooled to 15°C and diluted with ethyl acetate (40 ml), then washed twice with water (50 ml x 2). The aqueous phase was extracted with ethyl acetate (20 ml). The combined organic phases were dried over anhydrous sodium sulfate and concentrated to obtain a residue which was purified by silica gel column (petroleum ether:ethyl acetate = 10:1 to 1:1) to give the title compound (1.65 g, 4.88 mmol, yield: 58.60%) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.18(d,J＝9.0Hz,1H),7.83(d,J＝2.9Hz,1H),7.37-7.29(m,5H),7.27- 7.22(m,1H),6.86(dd,J＝9.1,2.9Hz,1H),3.78-3.70(m,1H),3.70-3.61( m,2H),3.57-3.45(m,2H),3.27(d,J＝10.3Hz,1H),2.83-2.74(m,1H),2.6 9(td,J＝7.4,9.3Hz,1H),2.35(td,J＝12.5,9.0Hz,1H),1.98-1.82(m,5H)

Step 6:

5-(1-Benzyl-1,7-diazaspiro[4,4]nonan-7-yl)pyridin-2-amine

To a solution of 1-benzyl-7-(6-nitro-3-pyridinyl)-1,7-diazaspiro[4,4]nonane (2.60 g, 7.68 mmol, 1.00 equiv) in ethanol (40.00 mL) were added zinc powder (2.01 g, 30.73 mmol, 4.00 equiv) and ammonium chloride (4.11 g, 76.83 mmol, 10.00 equiv). The mixture was heated to 80°C and stirred for 3 hours. LCMS showed complete conversion of the starting material and the detection of the desired product. The reaction mixture was cooled to 15°C and diluted with ethanol (30 mL), then filtered. The filter cake was washed with ethanol (30 mL). The filtrate was concentrated to give a crude product which was purified by preparative HPLC (basic) to afford the title compound (560.00 mg, 1.72 mmol, 22.34% yield, 94.5% purity) as a red oil. ¹ H NMR (400MHz, CDCl ₃ )δ7.52(d,J＝2.8Hz,1H),7.36-7.28(m,4H),7.21-7.14(m,1H),6.86(dd,J＝8.8,3 .0Hz,1H),6.51(d,J＝8.7Hz,1H),3.98(br.s.,2H),3.74(d,J＝13.3Hz,1H),3.63( d,J＝13.2Hz,1H),3.47-3.38(m,2H),3.24(q,J＝8.6Hz,1H),3.04(d,J＝9.4Hz,1H) ,2.77-2.59(m,2H),2.37(s,1H),2.27(td,J＝12.5,8.6Hz,1H),2.02-1.75(m,6H)

Step 7:

Azo-(5-(1-benzyl-1,7-diazaspiro[4,4]nonan-7-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

Under nitrogen, to a solution of 5-(1-benzyl-1,7-diazaspiro[4,4]nonan-7-yl)pyridin-2-amine (370 mg, 1.20 mmol, 1.00 equiv) and 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2methyl-2H-indazole (438.84 mg, 1.44 mmol, 1.20 equiv) in tetrahydrofuran (20.00 ml) were added potassium tert-butoxide (403.84 mg, 3.60 mmol, 3.00 equiv) and [2-(2-aminoethyl)phenyl]-palladium chloride; 2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl complex (88.63 mg, 120.00 mmol, 0.10 equiv). The mixture was heated to 80°C and stirred for 18 hours. LCMS showed 9.9% starting material remaining and 33.6% of the desired product was detected. The reaction mixture was cooled to 15°C and diluted with water (20 mL) and ethyl acetate (20 mL), then filtered. The filtrate was separated and the aqueous phase was extracted twice with ethyl acetate (20 mL x 2). The combined organic phases were washed with saturated brine (10 mL) and then concentrated. The resulting residue was purified by preparative TLC (ethyl acetate:methanol = 10:1) to give the title compound (220.00 mg, 381.47 μmol, yield: 31.79%) as a brown solid. ¹ H NMR (400 MHz, CDCl ₃ )δ8.69(s,1H),8.34(d,J＝4.0Hz,1H),8.22(br.s.,1H),8.06(d,J＝9.3Hz,1H),7.89(br.s.,1H),7 .78-7.69(m,2H),7.40-7.29(m,4H),7.27-7.22(m,1H),7.00(dd,J＝2.9,9.0Hz,1H),4.17(s,3H), 3.74(br.s.,1H),3.70-3.59(m,1H),3.56-3.49(m,3H),3.33(q,J＝8.4Hz,1H),3.13(d,J＝9.2Hz,1 H),2.75(br.s.,1H),2.69(br.s.,1H),2.31(br.s.,1H),1.95-1.84(m,5H),1.60(d,J＝7.0Hz,6H)

Step 8:

Azo-(5-(1,7-diazaspiro[4.4]nonan-7-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-amine

A mixture of N-(5-(1-benzyl-1,7-diazaspiro[4.4]nonan-7-yl)-2-pyridinyl)-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine (220.00 mg, 381.47 μmol, 1.00 equiv), ammonium formate (481.12 mg, 7.63 mmol, 20.00 equiv) and wet Pd/C (220.00 mg) was stirred in tetrahydrofuran (22.00 mL) and methanol (22.00 mL) at 80° C. for 16 hours. LC-MS indicated the reaction was complete. The mixture was filtered and the filtrate was concentrated in vacuo to give the crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (30.00 mg, 80.56 μmol, yield: 21.12%, purity: 98%). ¹ H NMR (400 MHz, Methanol-d ₄ )δ8.92(s,1H),8.78(d,J＝3.5Hz,1H),8.41(d,J＝9.2Hz,1H),8.00-7.81(m,2 H),7.66(d,J＝2.5Hz,1H),7.55(d,J＝9.5Hz,1H),4.34(s,3H),3.93(d,J＝10.9 Hz,1H),3.80-3.67(m,2H),3.65-3.47(m,4H),2.64-2.54(m,1H),2.53-2.43( m,1H),2.35-2.18(m,4H),1.67(d,J＝7.0Hz,6H).LCMS(ESI)m/z:487.4(M+1).

Example 17

5-Fluoro-nitrogen-(5-(hexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-yl)-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 3-bromo-4-(2-hydroxyethoxy)pyrrolidine-1-carboxylate

To a solution of tert-butyl 2,5-dihydropyrrole-1-carboxylate (8.00 g, 47.28 mmol, 1.00 eq) in ethylene glycol (30.00 ml) was added nitrogen-bromosuccinimide (9.26 g, 52.01 mmol, 1.10 eq) in portions. The mixture was stirred at 15°C for 16 hours. LC-MS and TLC showed that the reaction was complete. Water (100 ml) was added to the mixture. The resulting mixture was stirred at 15°C for 0.5 hours and extracted with ethyl acetate (100 ml x 3). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to give the title compound (14.00 g, crude product) as a white oil. ¹ H NMR (400MHz, CDCl ₃ )δ4.31(br.s.,1H),4.17(d,J＝5.5Hz,1H),3.98-3.92(m,1H),3.87-3.82(m,1H),3.77-3.72(m,2H),3.71- 3.58(m,2H),3.57-3.39(m,1H),2.06-2.01(m,1H),1.49(d,J＝6.7Hz,9H).LCMS(ESI)m/z:264.0(M+1-56).

Step 2:

tert-Butyl 3-bromo-4-(2-(p-toluenesulfonyloxy)ethoxy)pyrrolidine-1-carboxylate

To a solution of tert-butyl 3-bromo-4-(2-hydroxyethoxy)pyrrolidine-1-carboxylate (14.00 g, 45.14 mmol, 1.00 eq), triethylamine (6.85 g, 67.71 mmol, 1.50 eq), and 4-dimethylaminopyridine (551.48 mg, 4.51 mmol, 0.10 eq) in toluene (100.00 ml) at 0°C was added p-toluenesulfonyl chloride (11.19 g, 58.68 mmol, 1.30 eq). The mixture was stirred at 10°C for 16 hours. LC-MS and TLC indicated the reaction was complete. The mixture was diluted with water (100 ml), and the aqueous layer was extracted with ethyl acetate (100 ml). The combined organic layers were washed with saturated aqueous sodium chloride (30 mL x 2), dried over sodium sulfate, and concentrated in vacuo to afford the crude product, which was purified by column chromatography (petroleum ether:ethyl acetate = 4:1) to afford the title compound (11.10 g, 23.90 mmol, 52.95% yield) as a white oil. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.81 (d, J = 8.3 Hz, 2H), 7.38 (d, J = 8.0 Hz, 2H), 4.19-4.11 (m, 3H), 4.10-4.02 (m, 1H), 3.90-3.66 (m, 5H), 3.45-3.29 (m, 1H), 2.48 (s, 3H), 1.49 (s, 9H). LCMS (ESI) m/z: 408.0 (M+1-56).

Step 3:

tert-Butyl 4-benzylhexahydropyrrolo[3,4-b][1,4]oxazine-6(2H)-carboxylate

Tert-butyl 3-bromo-4-(2-(p-toluenesulfonyloxy)ethoxy)pyrrolidine-1-carboxylate (11.10 g, 23.90 mmol, 1.00 equiv) and benzylamine (7.68 g, 71.70 mmol, 3.00 equiv) in xylene (150.00 mL) were stirred at 140°C for 16 hours. TLC and LC-MS indicated the reaction was complete. The mixture was concentrated in vacuo to give a residue, which was diluted with ethyl acetate (100 mL) and water (100 mL). The aqueous layer was extracted with ethyl acetate (100 mL x 2). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to give the crude product, which was purified by column chromatography (PE:EA = 20:1 to 4:1) to afford the title compound (5.80 g, 14.21 mmol, 59.45% yield, 78% purity) as a yellow oil. ¹ H NMR (400MHz, CDCl ₃ )δ7.81(d,J＝8.3Hz,2H),7.38(d,J＝8.0Hz,2H),4.19-4.11(m,3H),4.10-4.02(m,1H),3.9 0-3.66(m,5H),3.45-3.29(m,1H),2.48(s,3H),1.49(s,9H).LCMS(ESI)m/z:319.1(M+1).

Step 4:

4-Benzylhexahydropyrrolo[3,4-b][1,4]oxazine

To a solution of tert-butyl 4-benzylhexahydropyrrolo[3,4-b][1,4]oxazine-6(2H)-carboxylate (2.90 g, 9.11 mmol, 1.00 equiv) in ethyl acetate (30.00 mL) at 0°C was added hydrochloric acid/ethyl acetate (30.00 mL). The mixture was stirred at 10°C for 16 hours. LC-MS indicated the reaction was complete. The mixture was concentrated in vacuo to afford the title compound (2.60 g, 8.93 mmol, 98.00% yield, hydrochloride salt) as a white solid. LCMS (ESI) m/z: 219.3 (M+1).

Step 5:

4-Benzyl-6-(6-nitropyridin-3-yl)octahydropyrrolo[3,4-b][1,4]oxazine

A mixture of 4-benzylhexahydropyrrolo[3,4-b][1,4]oxazine (2.60 g, 8.93 mmol, 1.00 equiv, 2HCl), 5-bromo-2-nitro-pyridine (1.81 g, 8.93 mmol, 1.00 equiv), and triethylamine (3.61 g, 35.72 mmol, 4.00 equiv) in nitrogen-dimethylformamide (30.00 mL) was stirred at 80°C for 16 hours. LC-MS indicated the reaction was complete. The mixture was diluted with ethyl acetate (40 mL) and water (120 mL) and extracted with ethyl acetate (40 mL x 3). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to afford the crude product, which was purified by column chromatography (petroleum ether:ethyl acetate = 3:1 to 1:1) to afford the title compound (2.00 g, 5.88 mmol, 65.80% yield) as a yellow solid. LCMS (ESI) m/z: 341.1 (M+1).

Step 6:

5-(4-Benzylhexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-amine

A mixture of 4-benzyl-6-(6-nitropyridin-3-yl)octahydropyrrolo[3,4-b][1,4]oxazine (2.00 g, 5.88 mmol, 1.00 equiv), iron powder (1.64 g, 29.40 mmol, 5.00 equiv), and ammonium chloride (3.15 g, 58.80 mmol, 10.00 equiv) in ethanol (50.00 mL) and water (10.00 mL) was stirred at 80°C for 16 hours. LC-MS indicated the reaction was complete. The mixture was filtered and the filtrate was concentrated in vacuo to give the crude product, which was purified by preparative HPLC (trifluoroacetic acid) to afford the title compound (1.00 g, 3.13 mmol, 53.15% yield, 97% purity) as a brown oil. LCMS (ESI) m/z: 311.2 (M+1).

Step 7:

N-(5-(4-benzylhexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Under nitrogen protection, a solution of 5-(4-benzyl-hexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-amine (300.00 mg, 966.53 μmol, 1.00 equiv), 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methylindazole (Intermediate C) (294.55 mg, 966.53 μmol, 1.00 equiv), [2-(2-aminoethyl)phenyl]-chloropalladium; dicyclohexyl-[2-(2,4,6-triisopropyl)phenyl]phosphine (71.40 mg, 96.65 μmol, 0.10 equiv) and potassium tert-butoxide (325.36 mg, 2.90 mmol, 3.00 equiv) in tetrahydrofuran (30.00 ml) was stirred at 80° C. for 16 hours. LC-MS showed the reaction was complete. To the mixture were added water (30 mL) and ethyl acetate (30 mL) in sequence, and stirred at 20°C for 15 minutes, then filtered and separated. The aqueous layer was extracted with ethyl acetate (20 mL x 2). The combined organic layers were dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a crude product, which was purified by preparative TLC (dichloromethane:methanol = 10:1) to obtain the title compound (190.00 mg, 265.95 μmol, yield: 27.52%, purity: 81%) as a yellow solid. LCMS (ESI) m/z: 579.4 (M+1).

Step 8:

5-Fluoro-nitrogen-(5-(hexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-yl)-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

A mixture of N-(5-(4-benzylhexahydropyrrolo[3,4-b][1,4]oxazin-6(2H)-yl)pyridin-2-yl)-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine (160.00 mg, 276.49 μmol, 1.00 equiv), ammonium formate (348.38 mg, 5.53 mmol, 20.00 equiv), and wet Pd/C (15.00 mg) in tetrahydrofuran (16.00 mL) and methanol (16.00 mL) was stirred at 80°C for 16 hours. LC-MS indicated the formation of the desired product. The mixture was filtered and the filtrate was concentrated in vacuo to give a crude product, which was purified by preparative HPLC (hydrochloric acid) to give the title compound (20.00 mg, 40.94 μmol, yield: 14.81%, purity: 100%). ¹ H NMR (400 MHz, Methanol-d ₄ ) δ 8.89 (s, 1H), 8.75 (d, J = 3.6 Hz, 1H), 8.33 (d, J = 9.0 Hz, 1H), 7.90 (d, J = 7.7 Hz, 1H), 7.81 (d, J = 9.0 Hz, 1H), 7.62 (s, 1H), 7.54 (d, J = 9.4 Hz, 1H), 4.59 (br. s., 1H), 4.30 (s, 3H), 4.19 (br. s. ,1H),4.11(d,J＝11.9Hz,1H),3.97-3.79(m,3H),3.79-3.67(m,2H),3.58(d,J＝11.0Hz,1H), 3.51(br.s.,1H),3.28(d,J＝13.1Hz,1H),1.65(d,J＝6.9Hz,6H).LCMS(ESI)m/z:489.4(M+1).

Example 18

1-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-2-one

Step 1:

N-(5-bromo-2-pyridyl)-N-tert-butyloxycarbonylcarbamate

To a solution of 5-bromopyridin-2-amine (2.00 g, 11.56 mmol, 1.00 equiv), N,N-diisopropylethylamine (4.48 g, 34.68 mmol, 6.05 ml, 3.00 equiv) and dimethylaminopyridine (282.46 mg, 2.31 mmol, 0.20 equiv) in dichloromethane (30.00 ml) was added di-tert-butyl carbonate (7.57 g, 34.68 mmol, 7.97 ml, 3.00 equiv) at 0°C. The reaction mixture was stirred at 30°C for 16 hours. LC-MS and TLC showed that the reaction was complete. The mixture was concentrated in vacuo to give the crude product. It was purified by column separation (ethyl acetate: petroleum ether = 50:1) to give the title compound (2.00 g, 5.36 mmol, yield: 46.35%) as a white solid. ¹ H NMR (400MHz, CDCl ₃ ) δ 8.55 (d, J = 2.3 Hz, 1H), 7.86 (dd, J = 2.5, 8.4 Hz, 1H), 7.20 (d, J = 8.5 Hz, 1H), 1.47 (s, 18H). LCMS (ESI) m/z: 373.1 (M+1).

Step 2:

Benzyl 3-oxopiperazine-1-carboxylate

To a mixture of sodium carbonate (24.77 g, 233.73 mmol, 3.00 equiv), piperazin-2-one (7.80 g, 77.91 mmol, 1.00 equiv) in ethyl acetate (70.00 mL) and water (70.00 mL) at 0°C was added benzyl chloroformate (16.79 g, 93.49 mmol, 13.99 mL, 95% purity, 1.20 equiv). The reaction mixture was stirred at 30°C for 16 hours. TLC indicated the reaction was complete. The mixture was extracted with ethyl acetate (80 mL x 3). The combined organic layers were washed with saturated aqueous sodium chloride solution (80 mL x 3), dried over sodium sulfate, and concentrated in vacuo to give a crude product, which was slurried with (petroleum ether:ethyl acetate = 20:1, 80 mL). The resulting mixture was stirred at 30°C for 15 minutes and filtered. The solid was dried in vacuo to give the title compound (15.50 g, 66.17 mmol, yield: 84.93%) as a white solid.

Step 3:

4-[6-[Di(tert-butoxycarbonyl)amino]-3-pyridinyl]-3-oxo-piperazine-1-carboxylic acid benzyl ester

Under nitrogen protection, a mixture of benzyl 3-oxopiperazine-1-carboxylate (4.00 g, 17.08 mmol, 1.00 equiv), nitrogen-(5-bromo-2-pyridyl)-nitrogen-tert-butyloxycarbonylcarbamate (6.37 g, 17.08 mmol, 1.00 equiv), nitrogen, nitrogen-dimethylethane-1,2-diamine (602.09 mg, 6.83 mmol, 734.26 μL, 0.40 equiv), potassium carbonate (7.08 g, 51.24 mmol, 3.00 equiv) and CuI (650.42 mg, 3.42 mmol, 0.20 equiv) in dioxane (80.00 mL) was stirred at 100° C. for 16 hours. LC-MS showed the reaction was complete. The mixture was filtered and the filtrate was concentrated in vacuo to give a crude product, which was purified by preparative TLC (petroleum ether:ethyl acetate=1:1) to give a mixture of the title compound and mono-Boc product (3.20 g, crude). LCMS (ESI) m/z: 527.2 (M+1).

Step 4:

4-(6-Aminopyridin-3-yl)-3-oxo-piperazine-1-carboxylic acid benzyl ester

To a solution of 4-[6-[di(tert-butoxycarbonyl)amino]-3-pyridyl]-3-oxo-piperazine-1-carboxylic acid benzyl ester (3.20 g, 6.08 mmol, 1.00 eq) in dichloromethane (20.00 ml) was added trifluoroacetic acid (10.00 ml) at 0°C. The reaction mixture was stirred at 30°C for 2 hours. LC-MS showed that the reaction was complete. The reaction mixture was concentrated in vacuo to give a crude product, which was then diluted with dichloromethane. Potassium carbonate (10 g) was added to the mixture. The resulting mixture was stirred at 30°C for 15 minutes and filtered. The filtrate was concentrated in vacuo to give the title compound (2.00 g, crude product) as a brown oil. ¹ H NMR (400MHz, Methanol-d ₄ )δ7.87(d,J＝2.5Hz,1H),7.42-7.36(m,4H),7.25-7.13(m,2H),6.63(d,J＝8.8Hz,1H),5.21(s ,2H),4.28(br.s.,2H),3.88(br.s.,2H),3.73(t,J=5.3Hz,2H).LCMS(ESI)m/z:327.1(M+1).

Step 5:

Benzyl 4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)-3-oxopiperazine-1-carboxylate

Under nitrogen, a mixture of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methylindazole (Intermediate C) (1.60 g, 5.25 mmol, 1.00 equiv), benzyl-4-(6-aminopyridin-3-yl)-3-oxo-piperazine-1-carboxylate (2.06 g, 6.30 mmol, 1.20 equiv), cesium carbonate (5.13 g, 15.75 mmol, 3.00 equiv), XPhos (500.58 mg, 1.05 mmol, 0.20 equiv), and Pd(OAc) ₂ (117.87 mg, 525.00 μmol, 0.10 equiv) in dioxane (50.00 mL) was stirred at 110° C. for 16 hours. LC-MS showed the reaction was complete. The mixture was filtered, and the filtrate was concentrated in vacuo to obtain a crude product. The crude product was purified by column chromatography (dichloromethane:methanol = 20:1) to obtain the title compound (2.40 g, 3.59 mmol, yield: 68.42%, purity: 89%) as a yellow solid. ^1H NMR (400 MHz, CDCl ₃ ) δ 8.65 (s, 1H), 8.70 (s, 1H), 8.57 (d, J = 9.0 Hz, 1H), 8.45 (d, J = 3.8 Hz, 1H), 8.33 (d, J = 2.5 Hz, 1H), 8.05 (d, J = 9.2 Hz, 1H), 7.75 (d, J = 9.2 Hz, 1H), 7.67 (dd, J = 8.9, 2.6 Hz, 1H) ),7.47-7.31(m,5H),5.22(s,2H),4.37(s,2H),4.20(s,3H),3.93-3.86(m,2H),3.82 -3.72(m,2H),3.58-3.46(m,1H),1.61(d,J＝7.0Hz,6H).LCMS(ESI)m/z:595.2(M+1).

Step 6:

1-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazin-2-one

Under a hydrogen atmosphere, a mixture of benzyl 4-(6-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)-3-oxopiperazine-1-carboxylate (2.40 g, 3.59 mmol, 1.00 equiv) and wet Pd/C (400.00 mg, purity: 10%) in methanol (20.00 ml) and tetrahydrofuran (20.00 ml) was stirred at 30° C. for 16 hours. LC-MS showed the reaction was complete. The mixture was filtered, and the filtrate was concentrated in vacuo to give the crude product, which was diluted with dichloromethane (20 ml). To the mixture was added hydrochloric acid/ethyl acetate (5 mL, 4 M) dropwise, followed by concentration in vacuo to give a crude product, which was purified by preparative HPLC (hydrochloric acid) to give the title compound (1.25 g, 2.32 mmol, yield: 64.62%, purity: 99%, hydrochloride salt). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.92(s,1H),8.83(d,J＝3.6Hz,1H),8.63(d,J＝2.1Hz,1H),8.45(dd,J＝2.5,9.4Hz,1H),8.36(d,J＝9.3Hz,1H),7.86-7.78(m,1 H),7.67(d,J＝9.5Hz,1H),4.31(s,3H),4.20-4.10(m,4H),3.83-3.68(m,3H),1.66(d,J＝7.0Hz,6H).LCMS(ESI)m/z:461.2(M+1).

Example 19

Aza-[5-(3,8-diazabicyclo[3.2.1]octan-3-yl)-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 3-(6-nitro-3-pyridyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate

To a solution of tert-butyl 3,8-diazabicyclo[3.2.1]octane-8-carboxylate (1.00 g, 4.71 mmol, 1.00 equiv) in dimethyl sulfoxide (20.00 mL) were added triethylamine (1.43 g, 14.13 mmol, 3.00 equiv) and 5-bromo-2-nitro-pyridine (1.15 g, 5.65 mmol, 1.20 equiv). The mixture was stirred at 100°C for 16 hours. LCMS indicated the reaction was complete. After the mixture was cooled to 20°C, 40 mL of water was added. The aqueous phase was extracted with dichloromethane (50 mL x 2), washed with saturated brine (50 mL x 1), dried over anhydrous sodium sulfate, filtered, and concentrated. The crude product was purified by slurrying with methanol (2 mL x 3) to afford the title compound (639.00 mg, crude) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.18(d,J＝9.2Hz,1H),8.09(d,J＝3.0Hz,1H),7.15(dd,J＝9.2Hz,3.0Hz,1H),4.47(br.s.,2H),3.58(d,J＝1 0.0Hz,2H),3.27(br.s.,2H),2.12-1.99(m,2H),1.86-1.76(m,2H),1.49(s,9H).LCMS(ESI)m/z:335.2(M+1).

Step 2:

tert-Butyl 3-(6-amino-3-pyridyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate

To a solution of tert-butyl 3-(6-nitro-3-pyridyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (339.00 mg, 1.01 mmol, 1.00 equiv) in methanol (11.00 ml) was added palladium on carbon (50.00 mg) under hydrogen (15 psi). The reaction mixture was stirred at 20°C for 18 hours. LCMS indicated the reaction was complete. The mixture was filtered and concentrated to afford the title compound (287.00 mg, crude) as a purple solid. LCMS (ESI) m/z: 305.2 (M+1).

Step 3:

tert-Butyl 3-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate

Under nitrogen, to a solution of tert-butyl 3-(6-amino-3-pyridyl)-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (140.00 mg, 459.94 μmol, 1.00 eq) in dioxane were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (Intermediate C) (249.50 mg, 818.69 μmol, 1.78 eq), Xantphos (79.84 mg, 137.98 μmol, 0.30 eq), cesium carbonate (446.58 mg, 1.37 mmol, 2.98 eq) and Pd ₂ (dba) ₃ (63.18 mg, 68.99 μmol, 0.15 eq). The mixture was stirred at 110° C. for 18 hours. LCMS indicated complete reaction of the starting material, with no product detected. TLC indicated complete reaction of the starting material with the generation of two new spots. The reaction mixture was filtered, and the filter cake was dissolved in 10 mL of water. The aqueous phase was extracted with dichloromethane (10 mL x 2). The combined organic phases were washed with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to afford the title compound (25.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 573.3 (M+1).

Step 4:

Aza-[5-(3,8-diazabicyclo[3.2.1]octan-3-yl)-2-pyridinyl]-5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-amine

To a solution of tert-butyl 3-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]-3,8-diazabicyclo[3.2.1]octane-8-carboxylate (25.00 mg, 43.66 μmol, 1.00 equiv) in dichloromethane (2 mL) was added trifluoroacetic acid (765.00 mg, 6.71 mmol, 153.67 equiv). The mixture was stirred at 20°C for 0.5 h. LCMS indicated the reaction was complete. The reaction mixture was concentrated to give the crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (11.80 mg, 22.82 μmol, 52.27% yield, 91.39% purity). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.89(s,1H),8.77(d,J＝3.5Hz,1H),8.35(d,J＝9.2Hz,1H),8.25(dd,J＝9.5,2.1Hz,1H),7.87(d,J＝1.9Hz,1H),7.81(d,J＝9.0Hz,1H),7 .55(d,J＝9.5Hz,1H),4.30(s,5H),3.84-3.67(m,3H),3.36-3.32(m,2H),2.20(s,4H),1.64(d,J＝6.9Hz,6H).LCMS(ESI)m/z:473.3(M+1).

Example 20

5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitrogen-(4-methyl-5-piperazin-1-yl-2-pyridinyl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-4-methyl-3-pyridyl]piperazine-1-carboxylate

Under nitrogen protection, to a solution of tert-butyl 4-(6-amino-4-methyl-3-pyridyl]piperazine-1-carboxylate (200.00 mg, 684.04 μmol, 1.00 eq) in dioxane (5.00 mL) were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-2H-indazole (Intermediate C) (250.15 mg, 820.85 μmol, 1.20 eq), Pd ₂ (dba) ₃ (62.64 mg, 68.40 μmol, 0.10 equiv), Xantphos (79.16 mg, 136.81 μmol, 0.20 equiv), and cesium carbonate (445.75 mg, 1.37 mmol, 2.00 equiv). The mixture was stirred at 110°C for 16 hours. LCMS indicated the reaction was complete. The mixture was concentrated, and the crude product was purified by preparative TLC (ethyl acetate:petroleum ether = 2:1) to give the title compound (150.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 561.4 (M+1).

Step 2:

5-Fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)-nitrogen-(4-methyl-5-piperazin-1-yl-2-pyridinyl)pyrimidin-2-amine

To a solution of tert-butyl 4-[6-[[5-fluoro-4-(3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-4-methyl-3-pyridyl]piperazine-1-carboxylate (150.00 mg, 267.54 μmol, 1.00 equiv) in dichloromethane (4 mL) at 20°C was added trifluoroacetic acid (1.53 g, 13.42 mmol, 50.16 equiv). The reaction mixture was stirred for 0.5 h. LCMS indicated the reaction was complete. The mixture was concentrated to give the crude product, which was purified by preparative HPLC (hydrochloric acid) to give the title compound (111.60 mg, 224.54 μmol, 83.93% yield, 100% purity, hydrochloride salt). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.93(s,1H),8.83(d,J＝3.51Hz,1H),8.32-8.45(m,3H),7.85(d,J＝9.03Hz,1H),7.62(d,J＝9.16Hz,1H),4.33(s,3H),3.74(d,J＝6.99Hz,1H) ,3.57(d,J＝12.67Hz,2H),3.10-3.27(m,3H),2.20(d,J＝13.68Hz,2H),1.96-2.10(m,2H),1.66(d,J＝7.03Hz,6H).LCMS(ESI)m/z:446.2(M+1).

Plan B

Preparation of 5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyridin-2-amine:

Example 21

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyridin-2-amine

Step 1:

5-(2-chloro-5-fluoropyridin-4-yl)-2-methyl-3-isopropenyl-2-hydrogen-indazole

Under nitrogen, to a mixed solution of 2-methyl-3-isopropenyl-5-boronic acid ester-2-hydrogen-indazole (500.00 mg, 1.68 mmol, 1.00 equiv) in dioxane (10 mL) and water (2 mL) were added 2-chloro-5-fluoro-4-iodo-pyridine (518.98 mg, 2.02 mmol, 1.20 equiv), _K₂CO₃ (696.58 mg, 5.04 mmol, 3.00 equiv), and Pd(dppf) _Cl₂ (122.93 mg, 168.00 μmol, 0.10 equiv). The mixture was stirred at 110°C for 3 hours. LCMS indicated the reaction was complete. The _mixture was cooled to 20°C, then water (10 mL) was added and extracted with ethyl acetate (15 mL x 3). The combined organic phases were washed with brine (15 mL x 2), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated to obtain a residue, which was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 30:1 to 5:1) to afford the title product (500 mg, 1.66 mmol, yield: 98.63%) as a yellow oil. ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.32 (d, J = 2.1 Hz, 1H), 7.89 (s, 1H), 7.77 (dd, J = 9.0, 0.8 Hz, 1H), 7.52-7.47 (m, 2H), 5.69 (t, J = 1.5 Hz, 1H), 5.35 (s, 1H), 4.22 (s, 3H), 2.30 (d, J = 1.0 Hz, 3H). LCMS (ESI) m/z: 302.0 (M+1).

Step 2:

5-(2-chloro-5-fluoropyridin-4-yl)-3-isopropyl-2-methyl-2-hydrogen-indazole

To a mixed solution of 5-(2-chloro-5-fluoropyridin-4-yl)-2-methyl-3-isopropenyl-2-hydrogen-indazole (500 mg, 1.66 mmol, 1.00 equiv) in methanol (5 mL) and tetrahydrofuran (5 mL) was added Rh(PPh ₃ ) ₃ Cl (153.59 mg, 166.00 μmol, 0.1 equiv). Hydrogen was introduced into the system at 50 psi, and the mixture was stirred at 50°C for 16 hours. LCMS indicated the reaction was complete. The mixture was cooled to 20°C and concentrated to a residue. The residue was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 20:1 to 5:1) to afford the title compound (460.00 mg, 1.51 mmol, yield: 91.23%) as a white oil. ¹ H NMR (400MHz, CDCl ₃ )δ8.33(d,J＝2.3Hz,1H),8.05(s,1H),7.75(dd,J＝9.0,0.8Hz,1H),7.50(d,J＝5.6Hz,1H),7.45(td,J ＝9.0,1.7Hz,1H),4.20(s,3H),3.55-3.48(m,1H),1.58(d,J＝7.0Hz,6H).LCMS(ESI)m/z:304.0(M+1).

Step 3:

tert-Butyl 4-(5-((5-fluoro-4-(3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyridin-2-yl)amino)pyridin-2-yl)piperazine-1-carboxylate

Under nitrogen, to a solution of 5-(2-chloro-5-fluoropyridin-4-yl)-3-isopropyl-2-methyl-2-hydrogen-indazole (200.00 mg, 658.41 μmol, 1.00 equiv) and tert-butyl 4-(6-amino-3-pyridyl)piperazine-1-carboxylate (274.90 mg, 987.62 μmol, 1.50 equiv) in dioxane (8 ml) were added Cs ₂ CO ₃ (643.57 mg, 1.98 mmol, 3.00 equiv), Xantphos (76.19 mg, 131.68 μmol, 0.20 equiv), and Pd ₂ (dba) ₃ (60.29 mg, 65.84 μmol, 0.10 equiv), and the mixture was stirred at 110° C. for 16 hours. LCMS showed the reaction was complete, and the mixture was cooled to 20°C and filtered. The filter cake was washed with ethyl acetate, and the filtrate was concentrated to give the title compound (350.00 mg, crude) as a black oil, which was used in the next step without purification. LCMS (ESI) m/z: 546.4 (M+1).

Step 4:

5-Fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyridin-2-amine

To a solution of tert-butyl 4-(5-((5-fluoro-4-(3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyridin-2-yl)amino)pyridin-2-yl)piperazine-1-carboxylate (350.00 mg, 641.44 μmol, 1.00 equiv) in dichloromethane (5 mL) was added trifluoroacetic acid (2.0 mL), and the mixture was stirred at 20° C. for 0.5 hours. LCMS showed that the reaction was complete. The mixture was concentrated under reduced pressure to remove dichloromethane and trifluoroacetic acid to obtain a residue. The residue was purified by preparative HPLC (hydrochloric acid) to obtain the title compound (250.00 mg, 558.27 μmol, yield: 87.03%, purity: 99.49%). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.47(d,J＝2.6Hz,1H),8.39(s,1H),8.21(dd,J＝9.7,2.9Hz,1H),7.89(d,J＝2.8Hz,1H),7.87-7.80(m,2H),7.44(d,J＝9.5Hz,1H),7.40( d,J＝5.5Hz,1H),4.31(s,3H),3.76-3.69(m,1H),3.56-3.51(m,4H),3.50-3.45(m,4H),1.64(d,J＝7.0Hz,6H).LCMS(ESI)m/z:304.0(M+1).

Plan C

General method for preparing intermediate D:

Step 1:

5-Bromo-2,3-difluorobenzaldehyde

2,3-Difluorobenzaldehyde (3.00 g, 21.22 mmol, 1.00 eq) was dissolved in sulfuric acid (18.4 mol/L, 10.20 ml, 8.89 eq) and heated to 60°C over 40 minutes. 1-Bromopyrrolidine-2,5-dione (4.51 g, 25.33 mmol, 1.20 eq) was then added in three portions over 20 minutes. Heating was carried out under nitrogen for 3 hours. TLC and HPLC indicated the reaction was complete. The reaction mixture was poured into ice water and extracted twice with petroleum ether (30 ml x 2), washed with water (30 ml x 2) and saturated brine (30 ml x 2), and then concentrated under reduced pressure. The residue was purified by column chromatography (petroleum ether) to yield the title compound (2.10 g, 9.50 mmol, 45.00% yield) as a yellow liquid. ¹ H NMR (400MHz, CDCl ₃ ) δ10.29(s,1H),7.77(br s,1H),7.65-7.54(m,1H).

Step 2:

(trans)-5-bromo-2,3-difluorobenzaldehyde-oxy-methyloxime

A mixture of 5-bromo-2,3-difluoro-benzaldehyde (1.50 g, 6.79 mmol, 1.00 equiv), oxymethylhydroxylamine (680.52 mg, 8.15 mmol, 1.20 equiv), and potassium carbonate (1.13 g, 8.15 mmol, 1.20 equiv) in dimethyl ether (20.00 ml) was heated to 40°C and stirred for 14 hours. TLC indicated that approximately 1% of the starting material had not reacted. The reaction mixture was filtered, and the filtrate was concentrated under reduced pressure to afford the title compound (1.00 g, crude product), which was used in the next step without further purification. ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.22 (s, 1H), 7.77-7.75 (m, 1H), 7.35-7.27 (m, 1H), 4.04 (s, 3H).

Step 3:

5-Bromo-7-fluoro-2-hydrogen-indazole

A solution of (trans)-5-bromo-2,3-difluorobenzaldehyde-oxy-methyloxime (4.90 g, 19.60 mmol, 1.00 equiv) in tetrahydrofuran (35.00 mL) and hydrazine hydrate (20.60 g, 411.51 mmol, 21.00 equiv, 85% specific) was heated to 90°C and stirred for 72 hours. LCMS indicated that 20% of the starting material had not reacted. The organic solvent was evaporated, and the resulting mixture was diluted with ethyl acetate (20 mL), washed with water (20 mL x 2), and concentrated under reduced pressure to obtain a residue. This residue was purified by column chromatography (petroleum ether:ethyl acetate = 60:1 to 40:1) to yield the title compound (3.25 g, 12.09 mmol, 61.69% yield, 80% purity) as a white solid. LCMS (ESI) m/z: 215.0 (M+1).

Step 4:

5-Bromo-7-fluoro-2-methyl-2-hydrogen-indazole

To a solution of 5-bromo-7-fluoro-2-hydrogen-indazole (1.10 g, 5.12 mmol, 1.00 equiv) and sodium methoxide (552.71 mg, 10.23 mmol, 2.00 equiv) in methanol (20.00 mL) was added iodomethane (1.09 g, 7.67 mmol, 1.50 equiv) dropwise under nitrogen at 30°C over 30 minutes. The mixture was heated to 85°C over 30 minutes and stirred for 5 hours. LCMS indicated that approximately 3% of the starting material had not reacted. The reaction mixture was cooled to 30°C and concentrated to dryness under reduced pressure, diluted with 3% aqueous sodium bicarbonate solution, and extracted with ethyl acetate (20 mL x 2). The organic phase was concentrated under reduced pressure to obtain a residue, which was purified by column chromatography (petroleum ether:ethyl acetate = 20:1 to 5:1) to afford the title compound (360.00 mg, 1.57 mmol, 30.66% yield) as a yellow solid. LCMS (ESI) m/z: 229.0 (M+1).

Step 5:

5-Bromo-7-fluoro-3-iodo-2-methyl-2-hydrogen-indazole

To a solution of 5-bromo-7-fluoro-2-methyl-2-hydrogen-indazole (500.00 mg, 2.18 mmol, 1.00 equiv) in dichloromethane (5.00 mL) was added pyridine (259.00 mL, 3.27 mmol, 1.50 equiv) and bis(trifluoroacetoxy)iodobenzene (1.13 g, 2.62 mmol, 1.20 equiv) at 30°C and stirred for 30 minutes. Iodine (664.86 mg, 2.62 mmol, 1.20 equiv) was added at 30°C and stirred for 23.5 hours. LCMS indicated complete conversion of the starting material. The reaction mixture was filtered to obtain a filter cake, which was washed with a solvent (petroleum ether:dichloromethane = 2:1, 10 mL) to afford the title compound (300.00 mg, 828.31 μmol, 38.00% yield, 98% purity) as a white solid. LCMS (ESI) m/z: 354.8 (M+1).

Step 6:

6-Bromo-4-fluoro-2-methyl-3-(propen-2-yl)-2-hydrogen-indazole

To a solution of 5-bromo-7-fluoro-3-iodo-2-methyl-2-hydrogen-indazole (320.00 mg, 901.56 μmol, 1.00 equiv) and 2-isopropenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (181.80 mg, 1.08 mmol, 1.20 equiv) in tetrahydrofuran (8.00 mL) and water (5.00 μL) was added potassium carbonate (373.81 mg, 2.70 mmol, 3.00 equiv) and Pd(dppf) _Cl₂ (131.93 mg, 180.31 μmol, 0.20 equiv) under nitrogen. The reaction mixture was stirred at 50-60°C for 16 hours. LCMS indicated 55% of the desired product. TLC indicated complete conversion of the starting material. The mixture was filtered, and the filtrate was concentrated to dryness. The concentrated residue was purified by column chromatography (petroleum ether:ethyl acetate = 10:1) to afford the title compound (210.00 mg, 780.35 μmol, 86.56% yield) as a light brown liquid. LCMS (ESI) m/z: 268.9 (M+1).

Step 7:

4-Fluoro-2-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-(propen-2-yl)-2-hydrogen-indazole

To a solution of 5-bromo-7-fluoro-3-isopropenyl-2-methyl-2H-indazole (302.00 mg, 1.12 mmol, 1.00 equiv) and bispinacol boronate (341.30 mg, 1.34 mmol, 1.20 equiv) in tetrahydrofuran (10.00 ml) was added three drops of water, Pd(dppf) _Cl₂ (163.90 mg, 224.00 μmol, 0.20 equiv), and potassium acetate (329.75 mg, 3.36 mmol, 3.00 equiv) under nitrogen. The mixture was stirred at 80-90°C for 14 hours. TLC (petroleum ether:ethyl acetate = 5:1) indicated that most of the starting material had reacted. The mixture was cooled to 25°C and filtered, and the filtrate was concentrated to dryness. The concentrated residue was purified by column chromatography (petroleum ether:ethyl acetate = 8:1) to afford the title compound (306.00 mg, 967.80 μmol, 86.41% yield) as a white solid. LCMS (ESI) m/z: 317.2 (M+1).

Step 8:

5-(2-chloro-5-fluoropyrimidin-4-yl)-7-fluoro-2-methyl-3-(propen-2-yl)-2-hydrogen-indazole

To a solution of 2,4-dichloro-5-fluoro-pyrimidine (177.44 mg, 1.06 mmol, 1.20 equiv) and 7-fluoro-3-isopropen-2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indazole (280.00 mg, 885.57 μmol, 1.00 equiv) in tetrahydrofuran was added potassium carbonate (367.18 mg, 2.66 mmol, 3.00 equiv), Pd(dppf) _Cl₂ (129.59 mg, 177.11 μmol, 0.20 equiv), and 3 drops of water under nitrogen. The mixture was stirred at 80-90°C for 16 hours. TLC (petroleum ether:ethyl acetate = 5:1) indicated the majority of the starting material was converted. The mixture was cooled to 25°C and filtered. The filter cake was washed with ethyl acetate (3 mL x 2), and the filtrate was concentrated to dryness. The residue was purified by column chromatography (petroleum ether:ethyl acetate = 7:1) to afford the title compound (Intermediate D) (260.00 mg, 802.57 μmol, 90.63% yield, 99% purity). LCMS (ESI) m/z: 320.9 (M+1).

Example 22

5-Fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-(6-((5-fluoro-4-(7-fluoro-2-methyl-3-(isopropen-2-yl)-2(hydrogen)-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate

Under nitrogen protection, to a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-7-fluoro-2-methyl-3-(isopropen-2-yl)-2-hydro-indazole (Intermediate D) (100 mg, 311.80 mmol, 1.00 equiv) in dioxane (3 ml) were added tert-butyl 4-(6-amino-3-pyridine)piperazine-1-carboxylate (99.81 mg, 358.57 mmol, 1.15 equiv), cesium carbonate (203.18 mg, 623.6 mmol, 2.00 equiv), Pd ₂ (dba) ₃ (57.1 mg, 62.36 μmol, 0.2 equiv) and Xantphos (72.17 mg, 124.72 μmol, 0.40 equiv). The mixture was replaced with nitrogen three times and heated to 100° C. and stirred for 18 hours. LCMS showed complete conversion of the starting material and detection of the desired product. The reaction solution was cooled to 25°C and diluted with dichloromethane (5 mL) before filtration. The filtrate was concentrated to obtain a residue which was purified by preparative TLC (ethyl acetate) to afford the title compound (100.00 mg, 177.74 μmol, yield: 57.01%) as a yellow solid. ¹ H NMR (400MHz, CDCl ₃ )δ8.38(d,J＝3.9Hz,1H),8.30(s,1H),8.03(d,J＝2.8Hz,1H),7.80(d,J＝12.7Hz,1H),7.38(dd,J＝9.0,2.9Hz,1H ),5.75-5.69(m,1H),5.37(s,1H),4.23(s,3H),3.67-3.56(m,4H),3.17-3.04(m,4H),2.31(s,3H),1.50(s,9H).

Step 2:

tert-Butyl 4-(6-((5-fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate

To a mixed solution of tert-butyl 4-(6-((5-fluoro-4-(7-fluoro-2-methyl-3-(isopropen-2-yl)-2hydro-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate (100.00 mg, 177.74 μmol, 1.00 eq) in methanol (10.00 ml) and acetic acid (500 μL) was added tris(triphenylphosphine)rhodium chloride (49.33 mg, 53.32 μmol, 0.3 eq). The reaction flask was purged with argon and hydrogen three times. Under a hydrogen pressure (50 Psi), the mixture was heated to 50° C. and stirred for 18 hours. LCMS showed complete conversion of the starting material and the target product was detected. The reaction solution was cooled to 25° C. and filtered. The residue obtained by concentration of the filtrate was purified by preparative TLC (ethyl acetate) to give the title compound (15 mg, crude product) as a yellow solid. LCMS (ESI) m/z: 565.3 (M+1).

Step 3:

5-Fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)-nitrogen-(5-(piperazin-1-yl)pyridin-2-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(6-((5-fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2-hydrogen-indazol-5-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperazine-1-carboxylate (15 mg, 26.57 μmol, 1.00 equiv) in dichloromethane (1 mL) was added trifluoroacetic acid (500 μL). The mixture was stirred at 25°C for 1 hour. LCMS indicated complete conversion of the starting material and detection of the desired product. The reaction solution was concentrated to obtain a residue which was purified by preparative HPLC (hydrochloric acid) to afford the title compound (3.88 mg, 8.27 μmol, yield: 31.12%, purity: 99%). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.73(d,J＝3.9Hz,1H),8.63(s,1H),8.27(dd,J＝2.6,9.7Hz,1H),7.91(d,J＝2.4Hz,1H),7.84(d,J＝13.2Hz,1H),7.55(d,J＝9.7 Hz,1H),4.22(s,3H),3.71-3.61(m,1H),3.60-3.51(m,4H),3.49-3.41(m,4H),1.59(d,J=7.0Hz,6H)LCMS(ESI)m/z:465.2(M+1).

Example 23

2-[4-[6-[[5-Fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]ethanol

Step 1:

2-[4-[6-[[5-Fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2H-indazol-5-yl)pyrimidin-2-yl]amino]-3-pyridinyl]piperazin-1-yl]ethanol

To a solution of 5-fluoro-4-(7-fluoro-3-isopropyl-2-methyl-2H-indazol-5-yl)-nitrogen-(5-piperazin-1-yl-2-pyridyl)pyrimidin-2-amine (80.00 mg, 172.22 μmol, 1.00 equiv) and 2-bromoethanol (64.56 mg, 516.66 μmol, 3.00 equiv) in acetonitrile (5.00 ml) was added diisopropylethylamine (66.77 mg, 516.66 μmol, 3.00 equiv). The mixture was heated to 70°C and stirred for 16 hours. LC-MS showed that the starting material was almost completely consumed and the MS of the desired compound was detected. The reaction mixture was concentrated under reduced pressure to obtain a residue. The residue was diluted with ethyl acetate (10 ml) and washed sequentially with water (5×3 ml) and brine (3×5 ml). The organic phase was dried over sodium sulfate, filtered, and the filtrate was concentrated to obtain a residue. The residue was purified by preparative HPLC (basic conditions) to give the title compound (20.31 mg, 39.14 μmol, yield: 22.72%, purity: 98%). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.59(s,1H),8.48(d,J＝3.5Hz,1H),8.18(d,J＝8.8Hz,1H),8.01(br.s,1H),7.80(d,J＝12. 5Hz,1H),7.73-7.63(m,1H),4.22(s,3H),3.76(t,J＝5.8Hz,2H),3.71-3.60(m,1H),3.24(br s,5H),2.76(br.s,4H),2.64(t,J＝5.5Hz,2H),1.60(d,J＝7.0Hz,6H).LCMS(ESI)m/z:509.3(M+1).

Plan D

General synthesis of intermediate E:

Step 1:

Benzyl 3-isobutyryl-4-oxopiperidine-1-carboxylate

To a solution of benzyl 4-oxopiperidine-1-carboxylate (128.07 g, 549.04 mmol, 1.95 equiv) in toluene (600.00 mL) was slowly added dropwise LiHMDS (550 mL, 550.00 mmol, 1.95 equiv) at 0°C. The mixture was stirred at 0°C for 1 hour. 2-Methylpropanoyl chloride (30.00 g, 281.56 mmol, 1.00 equiv) was then slowly added dropwise at 0°C. After the addition was complete, the mixture was heated to 25°C and stirred for 18 hours. TLC (petroleum ether:ethyl acetate = 5:1) indicated complete reaction of the starting material. The reaction was quenched by the addition of 10% aqueous acetic acid (100 mL). The layers were separated, and the organic layer was washed sequentially with water (500 mL) and saturated brine (500 mL). The resulting organic layer was dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated to obtain a residue, which was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1 to 20:1) to afford the title compound (57.00 g, crude product) as a pale yellow oil. ¹ H NMR (400 MHz, CDCl ₃ ) δ 16.10 (s, 1H), 7.38-7.36 (m, 5H), 5.18 (s, 2H), 4.33 (s, 2H), 3.69-3.66 (m, 2H), 2.68-2.57 (m, 1H), 2.48 (br s, 2H), 1.14 (d, J = 6.4 Hz, 6H).

Step 2:

Benzyl 6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridine-5(4-hydrogen)-carboxylate

To a solution of benzyl 3-isobutyryl-4-oxopiperidine-1-carboxylate (57.00 g, 187.90 mmol, 1.00 equiv) in ethanol (600.00 mL) at 25°C was added 40% aqueous methylhydrazine (110.00 g, 954.53 mmol, 5.08 equiv). The mixture was stirred for 1 hour. LCMS indicated complete reaction of the starting material. The reaction solution was concentrated to obtain a crude product, which was purified by preparative HPLC (trifluoroacetic acid) to yield an integrated solution. The acetonitrile in the integrated solution was concentrated, and the aqueous phase was adjusted to pH 8 with sodium bicarbonate, then extracted twice with dichloromethane (500 mL x 2). The combined organic layers were dried over sodium sulfate, filtered, and the filtrate concentrated to yield the title compound (6.50 g, 20.74 mmol, 11.4% yield) as a colorless oil. ¹ H NMR (400MHz, CDCl ₃ )δ7.43-7.29(m,5H),5.18(s,2H),4.58(s,2H),3.82-3.71(m,5H),3.03(quin,J＝7.0Hz,1H),2.82-2.67(m,2H),1.28(d,J＝6.4Hz,6H).

Step 3:

3-Isopropyl-2-methyl-4,5,6,7-tetrahydro-2-hydro-pyrazolo[4,3-c]pyridine

To a solution of benzyl 6,7-dihydro-3-isopropyl-2-methyl-2-hydro-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate (6.50 g, 20.74 mmol, 1.00 equiv) in methanol (100.00 ml) at 25°C were added palladium/carbonate (1.00 g) and 12 mol/L hydrochloric acid (1.00 ml). The atmosphere was replaced with nitrogen and then hydrogen three times, followed by a flow of hydrogen through the reaction mixture. The pressure in the reaction system was maintained at 50 psi and stirred for 2 hours. TLC (petroleum ether:ethyl acetate = 1:1) indicated complete reaction of the starting material. The reaction mixture was filtered, and the filtrate was concentrated to afford the title compound (5.25 g, crude) as an off-white solid. ¹ HNMR (400MHz, CDCl ₃ ) δ9.93 (br s, 2H), 4.31 (br s, 2H), 3.76 (s, 3H), 3.09-2.98 (m, 3H), 2.10 (br s, 2H), 1.26 (d, J = 7.0Hz, 6H).

Step 4:

5-(2-chloro-5-fluoropyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2-hydro-pyrazolo[4,3-c]pyridine

To a solution of 3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (5.25 g, 20.75 mmol, 1.00 equiv) in tetrahydrofuran (60.00 mL) was added 2,4-dichloro-5-fluoropyrimidine (3.50 g, 20.96 mmol, 1.01 equiv) and triethylamine (9.51 g, 94.01 mmol, 4.53 equiv) at 25°C. The reaction mixture was stirred for 18 hours. TLC (petroleum ether:ethyl acetate = 3:1) indicated complete reaction of the starting material. The reaction solution was diluted with water (200 mL) and extracted with ethyl acetate (200 mL x 2). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated to give a crude product, which was purified by column chromatography (petroleum ether:ethyl acetate = 5:1 to 2:1) to afford the title compound (Intermediate E) (5.60 g, 18.08 mmol, 87.12% yield) as an off-white solid. ¹ H NMR (300 MHz, CDCl ₃ ) δ 7.94 (d, J = 6.0 Hz, 1H), 4.84 (s, 2H), 4.03 (t, J = 5.8 Hz, 2H), 3.79 (s, 3H), 3.07 (spt, J = 7.1 Hz, 1H), 2.88 (t, J = 5.7 Hz, 2H), 1.32 (d, J = 7.2 Hz, 6H).

Example 24

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydropyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-N-(5-(1-methylpiperidin-4-yl)pyridin-2-yl)pyridin-2-amine

Step 1:

tert-Butyl 6-nitro-5',6'-dihydro-[3,4'-bipyridyl]-1'(2'hydro)carboxylate

Under nitrogen, to a mixed solution of 5-bromo-2-nitropyridine (10.00 g, 49.26 mmol, 1.02 equiv) in dioxane (120 mL) and water (10 mL) were added tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylate (15.00 g, 48.51 mmol, 1.00 equiv), potassium carbonate (5.9 g, 72.77 mmol, 1.50 equiv), and Pd(dppf) _Cl₂ (1.77 g, 2.43 mmol, 0.05 equiv). The reaction mixture was then heated to 80°C and stirred for 18 hours. TLC (petroleum ether:ethyl acetate = 3:1) indicated complete reaction of the starting material. The reaction solution was filtered, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product, which was purified by column chromatography (petroleum ether:ethyl acetate = 3:1) to afford the title compound (18.70 g, crude) as a pale yellow solid. ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.64 (d, J = 2.0 Hz, 1H) 8.24 (d, J = 8.4 Hz, 1H) 7.95 (dd, J = 8.5, 2.3 Hz, 1H) 6.33 (br s, 1H) 4.16 (d, J = 2.6 Hz, 2H) 3.69 (t, J = 5.6 Hz, 2H) 2.57 (br s, 2H) 1.50 (s, 9H).

Step 2:

tert-Butyl 4-(6-aminopyridin-3-yl)piperidine-1-carboxylate

To a solution of tert-butyl 4-(6-nitro-3-pyridyl)-3,6-dihydro-2-pyridine-1-carboxylate (18.70 g, 48.51 mmol, 1.00 equiv) in methanol (500 mL) was added Pd/C (2.00 g). The reaction system was flushed with nitrogen and then hydrogen three times. Hydrogen was introduced into the reaction solution, maintaining the pressure at 50 psi. The reaction mixture was heated to 50°C and stirred for 18 hours. LC-MS showed that the starting material was completely reacted. The mixture was filtered and the filtrate was concentrated to give the title compound (10.40 g, 37.50 mmol, 77.31% yield) as an off-white solid. ¹ H NMR (400MHz, CDCl ₃ ) δ7.92 (d, J = 2.4Hz, 1H) 7.31-7.27 (m, 1H) 6.48 (d, J = 8.5Hz, 1H) 4.35 (br s, 2H) 4.23 (br s,2H)2.78(t,J＝12.1Hz,2H)2.60-2.48(m,1H)1.78(br s,2H)1.61-1.52(m,2H)1.48(s,9H).

Step 3:

5-(1-methylpiperidin-4-yl)pyridin-2-amine

To a solution of lithium aluminum hydride (2.05 g, 54.09 mmol, 3.00 equiv) in tetrahydrofuran (100 mL) was slowly added dropwise a solution of tert-butyl 4-(6-amino-3-pyridyl)piperidine-1-carboxylate (5.00 g, 3.18 mmol, 1.00 equiv) in tetrahydrofuran (50 mL) at 0°C. After the addition was complete, the mixture was heated to 70°C and stirred for 2 hours. LC-MS indicated that the starting material had reacted completely. 20% aqueous potassium hydroxide (4 mL) was added to the reaction mixture at 0°C to quench the reaction, producing a large amount of solid. The reaction mixture was filtered and the filtrate concentrated to afford the title compound (4.00 g, crude) as a white solid. ¹ H NMR (400MHz, CDCl ₃ ) δ7.93 (d, J = 2.3Hz, 1H) 7.31 (dd, J = 8.4, 2.4Hz, 1H) 6.46 (d, J = 8.4Hz, 1H) 4.33 (br s,2H)2.95(d,J＝11.7Hz,2H)2.41-2.32(m,1H)2.31(s,3H)2.04-1.98(m,2H)1.80-1.67(m,4H).

Step 4:

5-Fluoro-4-(3-isopropyl-2-methyl-6,7-dihydro-2-hydropyrazolo[4,3-c]pyridin-5(4-hydro)-yl)-N-(5-(1-methylpiperidin-4-yl)pyridin-2-yl)pyrimidine

-2-amine

To a solution of 5-(2-chloro-5-fluoropyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (2.00 g, 6.46 mmol, 1.00 equiv) in toluene (20.00 ml) was added 5-(1-methyl-4-piperidinyl)pyridin-2-amine (1.36 g, 7.10 mmol, 1.10 equiv), cesium carbonate (4.21 g, 12.91 mmol, 2.00 equiv), Pd ₂ (dba) ₃ (400.00 mg, 436.81 μmol, 0.07 equiv) and Xantphos (520.00 mg, 898.69 μmol, 0.14 equiv) under nitrogen. The mixture was heated to 110° C. and stirred for 18 hours. LCMS indicated complete reaction of the starting material. The reaction mixture was cooled to 20°C and concentrated to afford a residue. This residue was purified by column chromatography (ethyl acetate to dichloromethane:methanol = 10:1) to afford a crude product, which was then purified by preparative HPLC (basic) to afford the title compound (2.48 g, 4.61 mmol, 71.42% yield). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.27(d,J＝1.9Hz,1H),8.13(d,J＝7.2Hz,1H),8.01(d,J＝8.5Hz,1H),7.45(d,J＝8.8Hz,1H),5.01(s,2H),4.16(t,J＝5.8Hz,2H),3.77(s,3H) ,3.65(d,J＝12.3Hz,2H),3.26-3.12(m,3H),3.09-2.98(m,1H),2.93(s,3H),2.86(t,J＝5.8Hz,2H),2.22-1.98(m,4H),1.34(d,J＝7.0Hz,6H).

Example 25

N-(5-Fluoro-4-(3-isopropyl-2-methyl-6,7-dihydro-2-hydro-pyrazolo[4,3-c]pyridin-5(4-hydro)-yl)pyrimidin-2-yl)-6-(4-methylpiperazin-1-yl)pyridazin-3-amine

Under nitrogen protection, to a solution of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (200.00 mg, 645.64 μmol, 1.00 eq) and 6-(4-methylpiperazin-1-yl)pyridazin-3-amine (124.77 mg, 645.64 μmol, 1.00 eq) in dioxane (5.00 ml) were added cesium carbonate (420.72 mg, 1.29 mmol, 2.00 eq), Pd ₂ (dba) ₃ (59.12 mg, 64.56 μmol, 0.10 eq) and Xantphos (74.72 mg, 129.13 μmol, 0.20 eq) were added, and the reaction mixture was heated to 110° C. and stirred for 16 hours. LCMS showed that the starting material had been reacted completely. The reaction mixture was cooled to 25° C., filtered, and concentrated under reduced pressure to give the crude product, which was purified by preparative HPLC (basic) to give the title compound (132.29 mg, 283.54 μmol, 43.92% yield). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.23(d,J＝9.91Hz,1H),7.93(d,J＝6.90Hz,1H),7.34(d,J＝9.91Hz,1H),4.85(s,2H),4.02(t,J＝5.84Hz,2H),3.77(s,3H),3.63-3.57(m ,4H),3.17(q,J＝7.00Hz,1H),2.81(t,J＝5.77Hz,2H),2.65-2.59(m,4H),2.38(s,3H),1.32(d,J＝7.03Hz,6H).LCMS(ESI)m/z:467.2(M+1).

Example 26

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-N-(5-(4-methyl-1,4-diazepan-1-yl)pyridin-2-yl)pyrimidin-2-amine

Step 1:

1-Methyl-4-(6-nitropyridin-3-yl)-1,4-diazacycloheptane

To a solution of 5-bromo-2-nitro-pyridine (2.00 g, 9.85 mmol, 1.00 equiv) and 1-methyl-1,4-diazacycloheptane (1.69 g, 14.78 mmol, 1.50 equiv) in dimethyl sulfoxide (20.00 ml) was added potassium carbonate (2.72 g, 19.70 mmol, 2.00 equiv). The mixture was heated to 80°C and stirred for 16 hours. LCMS indicated complete reaction of the starting material. The reaction mixture was cooled to 25°C and water (50 ml) was added, followed by extraction with ethyl acetate (100 ml x 3). The combined organic phases were washed with saturated brine (100 ml x 3), dried over anhydrous sodium sulfate, filtered, and concentrated to yield the crude product. This was purified by column chromatography (petroleum ether:ethyl acetate = 30:1 to 1:3) to give the title compound (2.00 g, 8.46 mmol, 85.94% yield) as a white solid. LCMS (ESI) m/z: 237.1 (M+1).

Step 2:

5-(4-methyl-1,4-diazepan-1-yl)pyridin-2-amine

To a solution of 1-methyl-4-(6-nitropyridin-3-yl)-1,4-diazepane (2.00 g, 8.46 mmol, 1.00 equiv) in methanol (20.00 mL) was added Pd/C (10%, 500 mg) at 25°C. The reaction system was flushed with nitrogen and then hydrogen three times, followed by a flow of hydrogen at 15 psi, and stirred for 2 hours. TLC indicated complete reaction of the starting material. The reaction mixture was filtered and concentrated under reduced pressure to afford the title compound (1.70 g, 8.24 mmol, 97.41% yield) as a white solid. LCMS (ESI) m/z: 207.1 (M+1).

Step 3:

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-N-(5-(4-methyl-1,4-diazepan-1-yl)pyridin-2-yl)pyrimidin-2-amine

Under nitrogen protection, to a solution of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (200.00 mg, 645.64 μmol, 1.00 eq) and 5-(4-methyl-1,4-diazepan-1-yl)pyridin-2-amine (159.83 mg, 774.77 μmol, 1.20 eq) in dioxane (5.00 ml) were added cesium carbonate (420.72 mg, 1.29 mmol, 2.00 eq), Pd ₂ (dba) ₃ (59.12 mg, 64.56 μmol, 0.10 eq) and Xantphos (74.72 mg, 129.13 μmol, 0.20 eq) were added, and the reaction mixture was heated to 110°C and stirred for 16 hours. LCMS showed that the starting material had been reacted completely. The reaction mixture was cooled to 25°C, filtered, and concentrated under reduced pressure to obtain the crude product. This was purified by preparative HPLC (basic) to obtain the title compound (93.10 mg, 194.12 μmol, 30.07% yield). ¹ H NMR (400 MHz, Methanol-d ₄ )δ7.91-7.84(m,2H),7.77(d,J＝3.01Hz,1H),7.22(dd,J＝9.16,3.14Hz,1H),4.85 (s,2H),4.01(t,J＝5.83Hz,2H),3.77(s,3H),3.62-3.57(m,2H),3.52(t,J＝6.27H z,2H),3.17(q,J＝7.03Hz,1H),2.83-2.75(m,4H),2.67-2.61(m,2H),2.40(s,3H) ,2.06(dt,J＝11.51,5.98Hz,2H),1.36-1.29(m,6H).LCMS(ESI)m/z:480.2(M+1).

Example 27

N-(5-(4-(Dimethylamino)piperidin-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

Step 1:

N,N-Dimethyl-1-(6-nitropyridin-3-yl)piperidin-4-amine

To a solution of N,N-dimethylpiperidin-4-amine (100.00 mg, 779.97 μmol, 1.00 eq) and 5-bromo-2-nitropyridine (158.33 mg, 779.97 μmol, 1.00 eq) in dioxane (5 mL) were added BINAP (48.57 mg, 78.00 μmol, 0.10 eq), cesium carbonate (508.26 mg, 1.56 mmol, 2.00 eq), and Pd(OAc) _₂ (17.51 mg, 78.00 μmol, 0.10 eq) under nitrogen. The reaction mixture was then heated to 90° C. and stirred for 16 hours. TLC indicated complete reaction of the starting material. The reaction mixture was filtered and concentrated to give the crude product, which was purified by preparative TLC (dichloromethane:methanol = 10:1) to afford the title compound (125.00 mg, 499.40 μmol, 64.03% yield) as a yellow solid. ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.20-8.14 (m, 2H), 7.21 (dd, J = 9.2, 3.2 Hz, 1H), 3.99 (d, J = 13.2 Hz, 2H), 3.12-3.02 (m, 2H), 2.47-2.39 (m, 1H), 2.33 (s, 6H), 2.01 (d, J = 12.4 Hz, 2H), 1.70-1.64 (m, 2H). LCMS (ESI) m/z: 251.1 (M+1).

Step 2:

5-(4-(Dimethylamino)piperidin-1-yl)pyridin-2-amine

To a solution of N,N-dimethyl-1-(6-nitropyridin-3-yl)piperidin-4-amine (525.00 mg, 2.10 mmol, 1.00 equiv) in methanol (10 mL) was added Pd-C (10%, 100 mg). The reaction system was flushed with nitrogen and hydrogen three times, followed by hydrogen gas flow through the reaction solution, maintaining the pressure at 15 psi, and stirred for 4 hours. TLC indicated complete reaction of the starting material. The reaction mixture was filtered and the filtrate concentrated to afford the title compound (450.00 mg, 2.04 mmol, 97.27% yield) as a yellow solid. ¹ H NMR (400MHz, Methanol-d ₄ )δ7.65-7.61(m,1H),7.34(dd,J＝9.2,2.4Hz,1H),6.59(dd,J＝8.8,0.8Hz,1H),3.52-3.44(m,2H),2.65(dt,J＝12 .4,2.4Hz,2H),2.42-2.38(m,6H),2.05-1.98(m,2H),1.67(dq,J＝12.4,4.4Hz,2H).LCMS(ESI)m/z:221.0(M+1).

Step 3:

N-(5-(4-(Dimethylamino)piperidin-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

To a solution of a mixture of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (150.00 mg, 484.23 μmol, 1.00 eq) and 5-[4-(dimethylamino)-1-piperidinyl]pyridin-2-amine (128.02 mg, 581.08 μmol, 1.20 eq) in dioxane (5.00 ml) was added Pd ₂ (dba) ₃ under nitrogen. (44.34 mg, 48.42 μmol, 0.10 eq), cesium carbonate (315.54 mg, 968.46 μmol, 2.00 eq) and Xantphos (56.04 mg, 96.85 μmol, 0.20 eq) were added, and the reaction mixture was heated to 110° C. and stirred for 16 hours. LCMS showed that the starting material had been reacted completely. The reaction mixture was cooled to 25° C., filtered and concentrated to give the crude product, which was purified by preparative HPLC (formic acid) to give the title compound (81.64 mg, 165.39 μmol, 34.16% yield). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.01-7.86(m,3H),7.51(dd,J＝9.16,2.76Hz,1H),4.85(s,2H),4.06-3. 96(m,2H),3.84-3.72(m,5H),3.38-3.33(m,1H),3.17(dt,J＝14.02,6.98H z,1H),2.90(s,6H),2.85-2.77(m,4H),2.22(d,J＝12.05Hz,2H),1.90(qd, J＝12.03,3.70Hz,2H),1.32(d,J＝7.03Hz,6H).LCMS(ESI)m/z:494.2(M+1).

Example 28

Nitrogen ^5- (2-(dimethylamino)ethyl)-nitrogen ^2- (5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-yl)-nitrogen ⁵ -methylpyridine-2,5-diamine

Step 1:

N-(2-(dimethylamino)ethyl)-N-methyl-6-nitropyridin-3-amine

To a solution of 5-bromo-2-nitro-pyridine (2.00 g, 9.85 mmol, 1.00 eq) and N,N,N-trimethylethane-1,2-diamine (1.51 g, 14.78 mmol, 1.50 eq) in dimethylformamide (20.00 ml) was added potassium carbonate (2.72 g, 19.70 mmol, 2.00 eq) in one portion. The reaction mixture was heated to 90°C and stirred for 16 hours. LCMS showed that the reaction was complete. After the reaction solution was cooled to 25°C, water (50 ml) was added to the reaction solution. The reaction mixture was extracted with ethyl acetate (100 ml x 3). The organic phases were combined and washed with saturated brine (100 ml x 3), then dried over anhydrous sodium sulfate, filtered, and concentrated to give a crude product. The crude product was purified by column chromatography (petroleum ether:ethyl acetate = 30:1 to 1:3) to give the title compound (1.50 g, 6.69 mmol, 67.91% yield) as a white solid. ^1H NMR (400 MHz, CDCl ₃ ): δ, 8.19-8.15 (m, 1H), 7.99 (d, J = 3.14 Hz, 1H), 7.02 (dd, J = 9.29, 3.14 Hz, 1H), 3.63-3.57 (m, 2H), 3.16 (s, 3H), 2.57-2.51 (m, 2H), 2.31 (s, 6H). LCMS (ESI) m/z: 225.1 (M+1).

Step 2:

N ³ -(2-(dimethylamino)ethyl)-N ³ -methylpyridine-3,6-diamine

Under nitrogen, palladium/carbon (300 mg) was added to a solution of N,N,N'-trimethyl-N'-(6-nitro-3-pyridyl)ethane-1,2-diamine (1.50 g, 6.69 mmol, 1.00 equiv) in methanol (15.00 mL). The suspension was purged with _H₂ several times and then stirred at 25°C under _H₂ (1 atm) for 2 hours. TLC indicated the reaction was complete. The reaction solution was filtered and concentrated to afford the title compound (1.20 g, 6.18 mmol, 92.33% yield) as a white solid, which did not require further purification. LCMS (ESI) m/z: 195.1 (M+1).

Step 3:

N ⁵ -(2-(Dimethylamino)ethyl)-N ² -(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-yl)-N ⁵ -methylpyridine-2,5-diamine

In a microwave tube were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (150.00 mg, 484.23 μmol, 1.00 equiv), N ³ -(2-(dimethylamino)ethyl)-N ³ -methylpyridine-3,6-diamine (112.89 mg, 581.08 μmol, 1.20 equiv), cesium carbonate (315.54 mg, 968.46 μmol, 2.00 equiv), Pd ₂ (dba) ₃ (88.68 mg, 96.85 μmol, 0.20 eq) and Xantphos (56.04 mg, 96.85 μmol, 0.20 eq) in dioxane (5.00 ml). The reaction solution was replaced with nitrogen several times and then heated to 130°C and stirred for 2.5 hours. LCMS showed that the reaction was not completely reacted, with approximately 14% product. The reaction solution was cooled to 25°C, filtered, and concentrated to obtain a crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to obtain the title compound (91.63 mg, 7 μmol, yield 47%). ¹ H NMR (400 MHz, Methanol-d ₄ ): δ, 8.25 (d, J = 7.03Hz, 1H), 8.03 (dd, J = 9.54, 3.01Hz, 1H), 7.95 (d, J = 2.89Hz, 1H),7.46(d,J＝9.54Hz,1H),5.08(s,2H),4.25(t,J＝5.58Hz,2H),4.06(s,3H), 3.88(t,J＝7.22Hz,2H),3.45(t,J＝7.22Hz,2H),3.40-3.35(m,1H),3.15-3.07( m,5H),3.0-22.97(m,6H),1.43(d,J＝7.03Hz,6H).LCMS(ESI)m/z:468.3(M+1).

Example 29

4-(6-((5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydro-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-4-ol

Step 1:

tert-Butyl 4-(6-aminopyridin-3-yl)-4-hydroxypiperidine-carboxylate

To a solution of 5-bromopyridin-2-amine (1.00 g, 5.78 mmol, 1.00 equiv) in tetrahydrofuran (13.00 mL) at -70°C was slowly added n-butyllithium (2.5 M, 7.07 mL, 3.06 equiv) dropwise. After stirring at -70°C for 1.5 hours, the reaction was warmed to 25°C and stirred for 2 hours. LCMS indicated approximately 19% of the reactant remained. LCMS indicated several new spots, indicating approximately 8% of the product. The reaction was quenched with water and saturated ammonium chloride solution at -70°C, then returned to 25°C. The mixture was extracted with ethyl acetate (50 mL x 3), and the combined organic phases were washed with saturated brine (20 mL x 3), dried over anhydrous sodium sulfate, filtered, and concentrated to yield the crude product. The crude product was purified by preparative HPLC (basic) to yield the title compound (300.00 mg, 1.02 mmol, 17.69% yield) as a yellow oil. ¹ H NMR (300MHz, DMSO-d ₆ ): δ,7.98(d,J＝2.07Hz,1H),7.43(dd,J＝8.67,2.45Hz,1H),6.38(d,J＝8.67Hz,1H),5.75(s,2H),4.89(s,1H),3.79(d,J＝9.80Hz,2H),3.11(br s,2H),1.77-1.63(m,2H),1.62-1.52(m,2H),1.41(s,9H).LCMS(ESI)m/z:294.0(M+1).

Step 2:

4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydropyrazolo[4,3-c]pyridin-5(4-hydro)-yl)pyrimidin-2-ylaminopyridin-3-yl)-4-hydroxypiperidine-carboxylic acid tert-butyl ester

Under nitrogen protection, to a solution of 4-(6-amino-3-pyridyl)-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (130.00 mg, 443.14 μmol, 1.00 equiv) in dioxane (5.00 ml) were added 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (164.73 mg, 531.77 μmol, 1.20 equiv), Pd ₂ (dba) ₃ (40.58 mg, 44.31 μmol, 0.10 equiv), xantphos (51.28 mg, 88.62 μmol, 0.20 equiv), and cesium carbonate (288.77 mg, 886.28 μmol, 2.00 equiv). The reaction mixture was stirred at 110°C for 16 hours. LCMS indicated completion of the reaction and the presence of product. After the reaction solution was cooled to 25°C, it was filtered and the filtrate was concentrated to obtain the crude product. The crude product was purified by preparative TLC (dichloromethane:methanol = 10:1) to afford the title compound (220.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 567.2 (M+1).

Step 3:

4-(6-(5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5-(4-hydrogen)-yl)pyrimidin-2-ylaminopyridin-3-yl)piperidin-4-ol

To a solution of tert-butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydropyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-ylaminopyridin-3-yl)-4-hydroxypiperidine-carboxylate (220.00 mg, 388.23 μmol, 1.00 equiv) in dichloromethane (4.00 mL) was added trifluoroacetic acid (2.00 mL) at 0°C. The reaction mixture was heated to 25°C and stirred for one hour. LCMS showed that the reaction was complete and the product was detected. The reaction solution was concentrated to give a crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to give the title compound (115.01 mg, 246.51 μmol, 63.50% yield). ¹ H NMR (300 MHz, Methanol-d ₄ )δ8.53(d,J＝1.9Hz,1H),8.35(dd,J＝9.0,2.3Hz,1H),8.29(d,J＝6.6Hz,1H),7.50(d,J＝9.0Hz,1H),4.26(t,J＝5Hz,2H),4.07(s,3H ),3.60-3.32(m,7H),3.16-3.06(m,2H),2.47-2.30(m,2H),2.02(d,J＝13.8Hz,2H),1.49-1.40(m,6H).LCMS(ESI)m/z:467.2(M+1).

Example 30

Azo-(5-(1,4-diazacycloheptane-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

Step 1:

tert-Butyl 4-(6-nitropyridin-3-yl)-1,4-diazacycloheptane-1-carboxylate

To a solution of 5-bromo-2-nitro-pyridine (2.00 g, 9.85 mmol, 1.00 eq) and tert-butyl 1,4-diazacycloheptane-1-carboxylate (2.37 g, 11.82 mmol, 1.20 eq) in dimethyl sulfoxide (20.00 ml) was added potassium carbonate (2.72 g, 19.70 mmol, 2.00 eq) in one portion. The reaction mixture was heated to 80°C and stirred for 16 hours. LCMS showed that the reaction was complete and the product was detected. The reaction solution was cooled to 25°C, water (50 ml) was added to the reaction solution, and then extracted with ethyl acetate (100 ml × 3). The combined organic phase was washed with saturated brine (100 ml × 3), dried over anhydrous sodium sulfate, filtered, and concentrated to give a crude product. The crude product was purified by column chromatography (petroleum ether:ethyl acetate = 30:1 to 1:3) to afford the title compound (2.00 g, 6.20 mmol, 62.99% yield) as a white solid. LCMS (ESI) m/z: 323.1 (M+1).

Step 2:

tert-Butyl 4-(6-aminopyridin-3-yl)-1,4-diazacycloheptane-1-carboxylate

Under nitrogen protection, Pd/C (300 mg) was added to a solution of tert-butyl 4-(6-nitropyridin-3-yl)-1,4-diazepane-1-carboxylate (1.80 g, 5.58 mmol, 1.00 eq) in methanol (20.00 ml). The suspension was replaced with _H2 several times and then stirred at 25°C under _H2 (one atmosphere) protection for 2 hours. TLC showed that the reaction was complete and a new spot was generated. The reaction solution was filtered and the filtrate was concentrated to give the crude product (1.70 g, crude product) as a white solid. The crude product was not purified and was used directly in the next reaction. LCMS (ESI) m/z: 293.2 (M+1). Step 3:

tert-Butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-ylamino)pyridin-3-yl)-1,4-diazacycloheptane-1-carboxylate

Under nitrogen protection, to a solution of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-6,7-dihydro-4-hydro-4,5,6,7-tetrahydro-2-hydro-pyrazolo[4,3-c]pyridine (Intermediate E) (200.00 mg, 645.64 μmol, 1.00 eq) in dioxane (5.00 ml) were added 4-(6-aminopyridin-3-yl)-1,4-diazacycloheptane-1-carboxylic acid tert-butyl ester (226.53 mg, 774.77 μmol, 1.20 eq), Pd ₂ (dba) ₃ (59.12 mg, 164.56 μmol, 0.01 eq), cesium carbonate (420.72 mg, 1.29 mmol, 2.00 eq), and Xantphos (74.72 mg, 129.13 μmol, 0.20 eq). The reaction mixture was stirred at 110°C for 16 hours. LCMS indicated completion of the reaction and detection of the expected product. The reaction solution was cooled to 25°C, filtered, and the filtrate concentrated to obtain the crude product. The crude product was purified by preparative TLC (ethyl acetate) to yield the title compound (250.00 mg, crude) as a white solid. LCMS (ESI) m/z: 566.2 (M+1).

Step 4:

Azo-(5-(1,4-diazacycloheptane-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-ylamino)pyridin-3-yl)-1,4-diazepane-1-carboxylate (250.00 mg, 441.95 μmol, 1.00 equiv) in dichloromethane (5.00 ml) was added trifluoroacetic acid (3 ml) at 25°C under nitrogen. The reaction mixture was stirred at 25°C for half an hour. LCMS showed that the reaction was complete and the expected product was detected. The reaction solution was concentrated to obtain a crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to obtain the title compound (127.94 mg, 274.80 μmol, 62.18% yield). ^1H NMR (400 MHz, Methanol-d ₄ )δ8.23(d,J＝6.78Hz,1H),7.94(dd,J＝9.47,2.70Hz,1H),7.86(d,J＝2.64Hz,1H),7 .41(d,J＝9.41Hz,1H),5.04-5.14(m,2H),4.24(t,J＝5.21Hz,2H),4.06(s,3H),3.83 -3.94(m,2H),3.65(t,J＝6.02Hz,2H),3.45-3.53(m,2H),3.34-3.42(m,3H),3.06-3 .13(m,2H),2.24-2.33(m,2H),1.44(d,J＝7.03Hz,6H).LCMS(ESI)m/z:466.2(M+1).

Example 31

Nitrogen-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-yl)-5-(piperazin-1-yl)pyrazin-2-amine

Step 1:

tert-Butyl 4-(5-aminopyrazin-2-yl)piperazine-1-carboxylate

Under nitrogen, to a solution of tert-butyl 4-(5-bromopyrazin-2-yl)piperazine-1-carboxylate (10.00 g, 29.14 mmol, 1.00 equiv) and tri-tert-butylphosphonium tetrafluoroborate (2.54 g, 8.74 mmol, 0.30 equiv) in toluene (100.00 mL) were added LiHMDS (1 M, 60.00 mL, 2.06 equiv) and Pd ₂ (dba) ₃ (2.60 g, 2.84 mmol, 0.10 equiv). The reaction was stirred at 65°C for 16 hours. LCMS indicated the reaction was complete and the expected product was detected. The reaction mixture was cooled to 25°C, quenched by the addition of water (50 mL), and extracted with ethyl acetate (100 mL x 3). The combined organic phases were concentrated to dryness to yield the crude product. The crude product was purified by preparative HPLC (alkaline) to afford the title compound (5.00 g, 17.90 mmol, 61.43% yield) as an orange solid. LCMS (ESI) m/z: 280.1 (M+1).

Step 2:

tert-Butyl 4-(5-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-ylamino)pyrazin-2-yl)piperazine-1-carboxylate

To a solution of 5-(2-chloro-5-fluoro-pyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (Intermediate E) (500.00 mg, 1.61 mmol, 1.00 equiv), tert-butyl 4-(5-aminopyrazin-2-yl)piperazine-1-carboxylate (495.97 mg, 1.78 mmol, 1.10 equiv) in dioxane (16.00 mL) was added Pd ₂ (dba) ₃ (147.81 mg, 161.41 μmol, 0.10 equiv), BINAP (201.01 mg, 322.82 μmol, 0.20 equiv), sodium tert-butoxide (232.67 mg, 2.42 mmol, 1.50 equiv), and water (400.00 μL). The reaction system was purged with nitrogen for 2 minutes, then sealed and heated to 140°C with stirring for 4 hours. LCMS indicated that the reaction was complete and the expected product was detected. The reaction solution was filtered through celite (washed with ethyl acetate), and the filtrate was washed with water (20 mL). The organic phase was concentrated to dryness to obtain the crude product. The crude product was purified by preparative TLC (petroleum ether:ethyl acetate = 2:1) to obtain the title compound (800.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 553.3 (M+1).

Step 3:

Nitrogen-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-yl)-5-(piperazin-1-yl)pyrazin-2-amine

To a solution of tert-butyl 4-(5-((5-fluoro-4-(3-isopropyl-2-methyl-6,7-dihydro-2H-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-yl)amino)pyrazin-2-yl)piperazine-1-carboxylate (800.00 mg, 1.45 mmol, 1.00 equiv) in dichloromethane (15.00 mL) was added trifluoroacetic acid (23.03 g, 201.95 mmol, 139.28 equiv). The reaction mixture was stirred at 30°C for 7 hours. LCMS indicated that the reaction was complete and the desired product was detected. The reaction mixture was concentrated to dryness to obtain a crude product. The crude product was purified by preparative HPLC (hydrochloric acid) to afford the title compound (213.05 mg, 435.69 μmol, 30.05% yield). ¹ H NMR (400MHz, methanol–d ₄ ): δ8.26(s,1H),8.16-8.24(m,2H),5.20(s,2H),4.36(br s,2H),4.07(s,3H),3.84-3.98(m,4H),3.35-3.44(m,5H),3.15(br s.,2H),1.33-1.53(m,6H).LCMS(ESI)m/z:453.2(M+1).

Example 32

Nitrogen-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-yl)-5-(4-methylpiperazin-1-yl)pyrazin-2-amine

To a solution of 5-fluoro-4-(3-isopropyl-2-methyl-6,7-dihydro-2H-pyrazolo[4,3-c]pyridin-5(4H)-yl)-nitrogen-(5-(piperazin-1-yl)pyrazin-2-yl)pyrimidin-2-amine (250.00 mg, 552.45 μmol, 1.00 equiv) in methanol (25.00 mL) was added NaBH ₃ CN (69.43 mg, 1.10 mmol, 2.00 equiv), HCHO (24.89 mg, 828.68 μmol, 1.50 equiv), and trifluoroacetic acid (62.99 mg, 552.45 μmol, 1.00 equiv) at 30° C. The reaction mixture was stirred at 30° C. for 4 hours. LCMS showed the reaction was complete. The reaction mixture was concentrated to dryness, and the crude product was purified by preparative HPLC (hydrochloric acid) and then by silica gel column chromatography (petroleum ether:ethyl acetate = 1:1) to give the title compound (35.03 mg, 75.08 μmol, 13.59% yield). ¹ H NMR (400MHz, methanol-d ₄ )δ8.88(s,1H),7.97(d,J＝1.13Hz,1H),7.93(d,J＝6.90Hz,1H),4.04(t,J＝5.84Hz,2H),3.75-3.79(m,3H),3.57-3.67(m,4H),3.12 -3.22(m,1H),2.77-2.85(m,6H),2.52(s,3H),2.03(s,1H),1.33(d,J＝7.03Hz,6H),1.28-1.32(m,1H).LCMS(ESI)m/z:467.2(M+1).

Example 33

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-nitrogen-(4-methyl-5-(piperazin-1-yl)pyridin-2-yl)pyrimidin-2-amine

Step 1:

5-Bromo-4-methyl-2-nitropyridine

_{To H₂SO₄} (184.00 g, 1.88 mol, 23.39 equiv) cooled to 0°C was slowly added dropwise _H₂O₂ (58.06 g, 1.71 mol, 21.28 equiv), maintaining the temperature below -20°C. A mixture of 5-bromo-4-methylpyridin-2-amine (15.00 g, 80.20 mmol, 1.00 equiv) in _H₂SO₄ (100.00 mL) was then added. The reaction mixture was stirred in an ice bath for ₄₅ minutes before being warmed to 30°C. After three hours, the color of the reaction solution changed from grass green to bright yellow. Ice (500 _mL ) was added to the reaction mixture, and the precipitated solid was filtered, washed with water, and then dried under vacuum to afford the title compound (12.00 g, 55.29 mmol, 68.95% yield) as a bright orange solid, which was not further purified. LCMS(ESI)m/z:216.9(M+1),218.9(M+3).

Step 2:

tert-Butyl 4-(4-methyl-6-nitropyridin-3-yl)piperazine-1-carboxylate

To _a mixture of 5-bromo-4-methyl-2-nitropyridine (500.00 mg, 2.30 mmol, 1.00 equiv), tert-butyl piperazine-1-carboxylate (514.05 mg, 2.76 mmol, 1.20 equiv), BINAP (286.43 mg, 460.00 μmol, 0.20 equiv), and Cs ₂ CO ₃ (1.05 g, 3.22 mmol, 1.40 equiv) in dioxane (20.00 mL) was added Pd ₂ (dba) ₃ (210.62 mg, 230.00 μmol, 0.10 equiv) under N 2 protection. The reaction mixture was stirred at 110° C. under N ₂ protection for 16 hours. LCMS indicated the reaction was complete. The reaction mixture was cooled to 20°C and filtered. The filtrate was concentrated to dryness and purified on a TLC plate (petroleum ether:ethyl acetate = 4:1) to afford the title compound (420.00 mg, 1.30 mmol, 56.65% yield) as a yellow solid. LCMS (ESI) m/z: 323.0 (M+1).

Step 3:

tert-Butyl 4-(6-amino-4-methylpyridin-3-yl)piperazine-1-carboxylate

Under _N₂ protection, 10% Pd-C (200 mg) was added to a solution of tert-butyl 4-(4-methyl-6-nitropyridin-3-yl)piperazine-1-carboxylate (350.00 mg, 651.45 μmol, 1.00 equiv) in methanol (15.00 mL). The suspension was evacuated and filled with hydrogen, then stirred at 30°C under 15 psi of _H₂ for 1.5 hours. LCMS indicated the reaction was complete. The mixture was filtered, concentrated to dryness, and the crude product was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 1:1) to afford the title compound (125.00 mg, 427.53 μmol, 65.63% yield) as a yellow solid. LCMS (ESI) m/z: 293.2 (M+1).

Step 4:

tert-Butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-ylamino)-4-methylpyridin-3-yl)piperazine-1-carboxylate

To tert-butyl 4-(6-amino-4-methylpyridin-3-yl)piperazine-1-carboxylate (124.59 mg, 426.12 μmol, 1.10 equiv), 5-(2-chloro-5-fluoropyrimidin-4-yl)-3-isopropyl-2-methyl-4,5,6,7-tetrahydro-2hydro-pyrazolo[4,3-c]pyridine (Intermediate E) (120.00 mg, 387.38 μmol, 1.00 equiv), Pd ₂ (dba) ₃ (35.47 mg, 38.74 μmol, 0.10 equiv), Xantphos (44.83 mg, 77.48 μmol, 0.20 equiv) and Cs ₂ CO ₃ was added. A mixture of 2- _[ 4-[ ...

Step 5:

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-nitrogen-(4-methyl-5-(piperazin-1-yl)pyridin-2-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-methyl-2-hydro-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidin-2-ylamino)-4-methylpyridin-3-yl)piperazine-1-carboxylate (150.00 mg, 265.17 μmol, 1.00 equiv) in dichloromethane (7.50 mL) was added trifluoroacetic acid (11.52 g, 101.00 mmol, 380.87 equiv) dropwise. The reaction mixture was stirred at 30° C. for 2 hours. LCMS indicated the reaction was complete. The mixture was concentrated to dryness, and the resulting crude product was purified by preparative HPLC (formic acid) to afford the title compound (121.00 mg, 236.52 μmol, 89.19% yield) as a yellow oil. ¹ H NMR (400MHz, Methanol-d ₄ )δ8.15(d,J＝7.2Hz,1H),8.05(s,1H),7.24(s,1H),5.00(s,2H),4.16(t,J＝5.8Hz,2H),3.81(s,3H),3.51-3.39(m,4H),3.31- 3.24(m,4H),3.24-3.16(m,1H),2.89(t,J＝5.8Hz,2H),2.55-2.45(m,3H),1.36(d,J＝7.2Hz,6H).LCMS(ESI)m/z:466.2(M+1).

Plan E

Synthesis of 5-fluoro-4-(6,7-dihydro-3-isopropyl-2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-nitrogen-(5-(1-methylpiperidin-4-yl)pyridin-2-yl)pyrimidin-2-amine:

Example 34

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-nitrogen-(5-(1-methylpiperidin-4-yl)pyridin-2-yl)pyrimidin-2-amine

Step 1:

Benzyl 3,3-dimethyl-4-oxypiperidine-1-carboxylate

At 0 ° C, sodium hydroxide (719.88 mg, 18.00 mmol, 2.10 equiv) and potassium iodide (3.80 g, 26.74 mmol, 3.12 equiv) were added to a solution of benzyl 4-oxopiperidine-1-carboxylate (2.00 g, 8.57 mmol, 1.00 equiv) in tetrahydrofuran (25 ml) in one portion. The mixture was stirred at 30 ° C for 16 hours. LCMS showed that the reaction was complete. Ammonium chloride solution (50 ml) was added to the reaction mixture, followed by extraction with ethyl acetate (50 ml × 2). The organic phase was concentrated to dryness, and the resulting residue was purified by preparative TLC plate (petroleum ether: ethyl acetate = 6: 1) to give the title compound (870.00 mg, 3.33 mmol, 38.86% yield) as a transparent oil. ¹ H NMR (400MHz, Methanol-d ₄ )δ7.38-7.33(m,5H),5.19(s,2H),3.81-3.77(t,J=6.4Hz,2H),3.50-3.46(m,2H),2.50(s,2H),1.11-1.04(m,6H).LCMS(ESI)m/z:284.1(M+1).

Step 2:

Benzyl 5-(isobutyryl)-3,3-dimethyl-4-oxypiperidine-1-carboxylate

To a solution of benzyl 3,3-dimethyl-4-oxopiperidine-1-carboxylate (6.00 g, 22.96 mmol, 1.00 equiv) in toluene (150.00 mL) at 0°C was added LDA (2 M, 22.96 mL, 2.00 equiv) in one portion. The reaction mixture was stirred at this temperature for 30 minutes before the addition of isobutyryl chloride (3.67 g, 34.44 mmol, 1.50 equiv). The temperature was then slowly raised to 30°C and stirred for 16 hours. TLC (petroleum ether:ethyl acetate = 6:1) indicated the reaction was complete. The reaction mixture was quenched with ammonium chloride solution (80 mL) and extracted with ethyl acetate (100 mL x 2). The combined organic phases were concentrated to dryness, and the resulting crude product was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to afford the title compound (5.60 g, 16.90 mmol, 73.60% yield) as a yellow oil.

Step 3:

6,7-Dihydro-3-isopropyl 2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridine-5(4-hydrogen)-carboxylic acid benzyl ester

To a solution of benzyl 5-(isobutyryl)-3,3-dimethyl-4-oxopiperidine-1-carboxylate (3.90 g, 11.77 mmol, 1.00 equiv) and 40% aqueous methylhydrazine (13.99 g, 121.47 mmol, 10.32 equiv) in ethanol (35.00 ml) was added acetic acid (706.66 mg, 11.77 mmol, 1.00 equiv) in one portion. The reaction mixture was stirred at 32°C for 16 hours. LCMS indicated the reaction was complete. The reaction solution was concentrated to dryness, and the resulting crude product was purified by preparative TLC (petroleum ether:ethyl acetate = 5:1) to afford the title compound (600.00 mg, 1.76 mmol, 14.93% yield) as a clear oil. LCMS (ESI) m/z: 342.2 (M+1).

Step 4:

3-Isopropyl-2,7,7-trimethyl-4,5,6,7-tetrahydro-2-hydro-pyrazolo[4,3-c]pyridine

Under _N₂ protection, to a solution of benzyl 6,7-dihydro-3-isopropyl 2,7,7-trimethyl-2H-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate (600.00 mg, 1.76 mmol, 1.00 equiv) in methanol (20.00 mL) was added 10% Pd/C (0.4 g). The suspension was evacuated and filled with hydrogen, then stirred at 30°C under _H₂ (15 psi) for 2 hours. LCMS indicated the reaction was complete. The mixture was filtered and concentrated to dryness to afford the title compound (323.00 mg, 1.56 mmol, 88.53% yield) as a yellow oil. LCMS (ESI) m/z: 208.2 (M+1). Step 5:

5-(2-chloro-5-fluoropyrimidin-4-yl)-4,5,6,7-tetrahydro-3-isopropyl-2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridine

At 30 ° C, 3-isopropyl-2,7,7-trimethyl-4,5,6,7-tetrahydro-2hydro-pyrazolo[4,3-c]pyridine

To a solution of 2,4-dichloro-5-fluoropyrimidine (323.00 mg, 1.56 mmol, 1.00 equiv) and 2,4-dichloro-5-fluoropyrimidine (338.62 mg, 2.03 mmol, 1.30 equiv) in tetrahydrofuran (25.00 ml) was added triethylamine (1.58 g, 15.58 mmol, 10.00 equiv), and the reaction mixture was stirred at 30°C for 12 hours. LCMS indicated the reaction was complete. The reaction mixture was diluted with saturated brine (20 ml) and then extracted with ethyl acetate (50 ml x 2). The organic phases were combined and dried, and the resulting residue was purified by preparative TLC (petroleum ether:ethyl acetate = 4:1) to yield the title compound (380.00 mg, 1.12 mmol, 72.11% yield) as a yellow oil. LCMS (ESI) m/z: 338.1 (M+1).

Step 6:

5-Fluoro-4-(6,7-dihydro-3-isopropyl-2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)-nitrogen-(5-(1-methylpiperidin-4-yl)pyridin-2-yl)pyrimidin-2-amine

To a mixture of _5- (2-chloro-5-fluoropyrimidin-4-yl)-4,5,6,7-tetrahydro-3-isopropyl-2,7,7-trimethyl-2-hydrogen-pyrazolo[4,3-c]pyridine (380.00 mg, 1.12 mmol, 1.00 equiv), 5-(1-methylpiperidin-4-yl)pyridin-2-amine (257.07 mg, 1.34 mmol, 1.20 equiv ₎ and _Cs2CO3 (729.84 mg, 2.24 mmol, 2.00 equiv) in dioxane (25.00 ml) was added _Pd2 (dba) ₃ (102.56 mg, 112.00 mmol, 0.10 equiv) and Xantphos (129.61 mg, 224.00 μmol, 0.20 equiv) in one portion under N2 protection. The reaction mixture was flushed with _N₂ , and then stirred at 110°C for 16 hours. LCMS indicated the reaction was complete. Water (10 mL) was added to the reaction mixture for dilution, followed by extraction with ethyl acetate (50 mL x 2). The organic phases were combined and dried, and the resulting residue was purified by preparative HPLC (hydrochloric acid) and then by SFC (AD-3S_5_40_3ML, Column: Chiralpak AD-3100 x 4.6 mm I.D. 3 μm, Mobile phase: 40% ethanol (0.05% DEA) in _CO₂ , Flow rate: 3 mL/min, Wavelength: 220 nm) to afford the title compound (60.00 mg, 121.80 μmol, 10.87% yield). ¹ H NMR (400MHz, Methanol-d ₄ )δ8.36(s,1H),8.30(d,J＝6.8Hz,1H),8.27-8.19(m,1H),7.56-7.48(m, 1H),5.09(s,2H),4.12(s,3H),4.05(s,2H),3.73-3.60(m,2H),3.44-3. 35(m,1H),3.31-3.25(m,1H),3.21-3.09(m,1H),2.96(s,3H),2.35(s,1 H),2.26-2.08(m,4H),1.51-1.44(m,12H).LCMS(ESI)m/z:493.3(M+1).

Plan F

Synthesis of N-(5-(1,4-diazaheptane-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-phenyl-2-hydro-pyrazolo[4,3-c]pyridin-5(4-hydro)-yl)pyrimidin-2-amine:

Example 35

Azo-(5-(1,4-diazaheptane-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

Step 1:

Benzyl 6,7-dihydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate

To a solution of benzyl 3-(2-methylpropionyl)-4-oxo-piperidine-1-carboxylate (500.00 mg, 1.65 mmol, 1.00 equiv) in ethanol (5.00 ml) was added phenylhydrazine (178.24 mg, 1.65 mmol, 1.00 equiv). The reaction mixture was heated to 80°C and stirred at this temperature for 4 hours. TLC (petroleum ether:ethyl acetate = 2:1) and LCMS showed that the reaction was complete. The reaction mixture was cooled to 25°C and then concentrated under reduced pressure to remove the solvent. The resulting residue was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to give the title compound (330.00 mg, 878.92 μmol, 53.27% yield) as a red oil. ¹ H NMR (400MHz, CDCl ₃ ) δ7.50-7.36 (m, 10H), 5.23 (s, 2H), 4.70 (s, 2H), 3.83 (br s, 2H), 3.07 (q, J = 7.0Hz, 1H), 2.86 (br s,2H),1.28-1.20(m,6H).LCMS(ESI)m/z:376.1(M+1).

Step 2:

4,5,6,7-Tetrahydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridine

To a solution of benzyl 6,7-dihydro-3-isopropyl-2-phenyl-2-hydro-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate (330.0 mg, 878.92 μmol, 1.00 equiv) in methanol (5.00 mL) was added 10% palladium on carbon (50 mg). The reaction mixture was stirred at 25°C under _H₂ (15 psi) for 2 hours. TLC (dichloromethane:methanol = 10:1) indicated the reaction was complete. The reaction mixture was filtered, and the filtrate was concentrated to afford the title compound (200.00 mg, crude) as a yellow oil.

Step 3:

5-(2-Chloro-5-fluoropyrimidin-4-yl)-4,5,6,7-tetrahydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridine

To a solution of 4,5,6,7-tetrahydro-3-isopropyl-2-phenyl-2-hydro-pyrazolo[4,3-c]pyridine (200.00 mg, 828.74 μmol, 1.00 equiv) in tetrahydrofuran (5.00 mL) were added triethylamine (167.72 mg, 1.66 mmol, 2.00 equiv) and 2,4-dichloro-5-fluoro-pyrimidine (166.05 mg, 994.49 μmol, 1.20 equiv). The reaction mixture was stirred at 25°C for 2 hours. LCMS indicated the reaction was complete. The reaction mixture was concentrated to dryness, and the resulting residue was purified by preparative TLC (petroleum ether:ethyl acetate = 2:1) to afford the title compound (190.00 mg, 510.97 μmol, 61.66% yield) as a white solid. ¹ H NMR (400MHz, CDCl ₃ )δ7.99(d,J＝6.0Hz,1H),7.52-7.43(m,3H),7.40-7.36(m,2H),4.97(s,2H),4.12(t,J＝5.9Hz,2H) ,3.10(q,J＝7.1Hz,1H),2.99(t,J＝5.9Hz,2H),1.30(d,J＝7.0Hz,6H).LCMS(ESI)m/z:372.0(M+1).

Step 4:

tert-Butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidine 2-aminopyridin-3-yl)-1,4-diazepine-1-carboxylate

Under N ₂ protection, to a mixture of 5-(2-chloro-5-fluoropyrimidin-4-yl)-4,5,6,7-tetrahydro-3-isopropyl-2-phenyl-2hydro-pyrazolo[4,3-c]pyridine (190.00 mg, 510.97 μmol, 1.00 eq), tert-butyl 4-(6-amino-3-pyridinyl)-1,4-diazepine-1-carboxylate (224.10 mg, 766.46 μmol, 1.50 eq) in dioxane (5.00 ml) were added Cs ₂ CO ₃ (499.45 mg, 1.53 mmol, 3.00 eq), Xantphos (59.13 mg, 102.19 μmol, 0.20 eq), and Pd ₂ (dba) ₃ (46.79 mg, 51.10 μmol, 0.10 eq). The reaction mixture was heated to 120°C and stirred at this temperature for 16 hours. LCMS indicated the reaction was complete. The reaction mixture was filtered, and the filtrate was concentrated. The resulting residue was purified by preparative TLC (neat ethyl acetate) to afford the title compound (100.00 mg, crude) as a yellow solid. LCMS (ESI) m/z: 628.3 (M+1).

Step 5:

Azo-(5-(1,4-diazepan-1-yl)pyridin-2-yl)-5-fluoro-4-(6,7-dihydro-3-isopropyl-2-phenyl-2-hydrogen-pyrazolo[4,3-c]pyridin-5(4-hydrogen)-yl)pyrimidin-2-amine

To a solution of tert-butyl 4-(6-(5-fluoro-4-(6,7-dihydro-3-isopropyl-2-phenyl-2hydro-pyrazolo[4,3-c]pyridin-5(4H)-yl)pyrimidine 2-aminopyridin-3-yl)-1,4-diazepine-1-carboxylate (100.00 mg, 159.30 μmol, 1.00 equiv) in dichloromethane (3.00 mL) was added trifluoroacetic acid (1 mL). The reaction mixture was stirred at 25° C. for 0.5 h. LCMS showed that the reaction was complete. The reaction mixture was concentrated under reduced pressure to remove the solvent, and the resulting residue was purified by preparative HPLC (hydrochloric acid) to give the title compound (50.00 mg, 94.76 μmol, 59.49% yield). ¹ H NMR (400 MHz, Methanol-d ₄ )δ8.24(d,J＝6.8Hz,1H),7.92(dd,J＝9.4,2.8Hz,1H),7.86(d,J＝2.6Hz,1H),7.73-7.68(m,3H ),7.65-7.57(m,2H),7.39(d,J＝9.5Hz,1H),5.17(s,2H),4.31(t,J＝5.0Hz,2H),3.92-3.84(m, 2H),3.65(t,J＝6.0Hz,2H),3.52-3.45(m,2H),3.41-3.36(m,2H),3.14(t,J＝5.1Hz,2H),3.06( td,J＝14.0,6.9Hz,1H),2.33-2.24(m,2H),1.37(d,J＝7.0Hz,6H).LCMS(ESI)m/z:528.2(M+1).

Pharmacology

The compounds described herein are selective CDK4/6 inhibitors. For example, their activity against CDK2 enzymes is less than that against CDK4/6 ( _IC50 values compared). The following experimental results confirm that the compounds listed in this patent are indeed specific CDK4/6 inhibitors and are potential anticancer drugs. The _IC50 used herein refers to the concentration of an agent that produces 50% maximal inhibition. The compounds described herein also exhibit unexpected biological activities. For example, Example 13 is not an efflux transporter substrate, whereas palbociclib and LY2835219 have been shown to be efflux transporter substrates. Furthermore, the brain tissue exposure of Example 13 is significantly higher than that of palbociclib and LY2835219 at the same time. It is speculated that Example 13 has greater potential than palbociclib and LY2835219 for treating breast cancer with brain metastasis, which accounts for approximately 15% of breast cancer patients. The biological activities presented here are only representative of those of individual examples.

Biochemical experiments

Experimental Materials:

CDK2/cyclin A, CDK4/cyclin D1, and CDK6/cyclin D1 were assayed using Life Science. ULight-labeled peptide substrates ULight-4E-BP1 and ULight-MBP were used (PerkinElmer). Europium-labeled anti-myelin basic protein antibodies and europium-labeled rabbit antibodies were used (PerkinElmer). Signals were detected using the Envision Multilabel Analyzer (PerkinElmer).

Experimental methods:

The compounds to be tested were diluted three-fold, including 10 concentration gradients, with the final concentration range from 5 uM to 0.25 nM.

●CDK2/cyclin A enzyme reaction system

The standard Lance Ultra method was performed using a 10 μL enzyme reaction system containing 0.5 nM CDK2/cyclin A protein, 100 nM ULight-MBP peptide, and 25 μM ATP. Each reaction was dissolved in enzyme buffer consisting of 50 mM hydroxyethylpiperazine ethanesulfonic acid (pH 7.5), 1 mM EDTA, 10 mM magnesium chloride, 0.01% Brij-35, and 2 mM dithiothreitol. After initiation of the reaction, the OptiPlate 384-well plate was sealed with TopSeal-A and incubated at room temperature for 60 minutes.

●CDK4/cyclin D1 enzyme reaction system

The standard Lance Ultra method was performed using a 10 μL enzyme reaction containing 0.3 nM CDK4/cyclin D1 protein, 50 nM ULight-4E-BP1 peptide, and 350 μM ATP. These were dissolved in enzyme buffer consisting of 50 mM hydroxyethylpiperazine ethanesulfonic acid (pH 7.5), 1 mM EDTA, 10 mM magnesium chloride, 0.01% Brij-35, and 2 mM dithiothreitol. After initiation of the reaction, the OptiPlate 384-well plate was sealed with TopSeal-A and incubated at room temperature for 180 minutes.

CDK6/cyclin D1 enzyme reaction system

The standard Lance Ultra method was performed using a 10 μL enzyme reaction containing 0.8 nM CDK6/cyclin D1 protein, 50 nM ULight-4E-BP1 peptide, and 250 μM ATP. Each reaction was dissolved in enzyme buffer consisting of 50 mM hydroxyethylpiperazine ethanesulfonic acid (pH 7.5), 1 mM EDTA, 10 mM magnesium chloride, 0.01% Brij-35, and 2 mM dithiothreitol. After initiation of the reaction, the OptiPlate 384-well plate was sealed with TopSeal-A and incubated at room temperature for 180 minutes.

Prepare enzyme reaction stop buffer and dissolve EDTA in a 1x dilution of assay buffer. Terminate the reaction at room temperature for 5 minutes. Add 5 μL of the assay mix (prepared with europium-labeled anti-MYB antibody and europium-labeled rabbit antibody, respectively) to each CDK2/cyclin A, CDK4/cyclin D1, and CDK6/cyclin D1 reaction. Incubate at room temperature for 60 minutes. Detect the reaction signal using time-resolved fluorescence resonance energy transfer (TRFE) using an Envision instrument.

Data Analysis:

The raw data were converted to inhibition ratios using the equation (Max-Ratio)/(Max-Min)*100%. IC50 values were then derived by four-parameter curve fitting (derived using the 205 model in XLFIT5, iDBS). Table 1 provides the inhibitory activities of the compounds of the present invention against CDK2/CDK4/CDK6 kinases.

Cell experiments

Experimental Materials:

RPMI 1640 medium, fetal bovine serum, and penicillin/streptomycin antibiotics were purchased from Promega (Madison, WI). MCF-7 and MDA-MB-436 cell lines were purchased from the European Collection of Cell Cultures (ECACC). Envision multi-label analyzer (PerkinElmer) was used.

Experimental methods:

MCF-7 cells were seeded in black 384-well plates, with 45 μL of cell suspension per well, containing 200 MCF-7 cells. The plates were cultured in a CO2 incubator overnight.

Test compounds were diluted 3-fold with Bravo to the 10th concentration, from 10 μM to 0.508 nM, in duplicate. 49 μL of culture medium was added to the middle plate. 1 μL of the serially diluted compound was transferred to each well of the middle plate, mixed thoroughly, and then 5 μL was transferred to each well of the cell plate. The cell plate was cultured in a CO2 incubator for 6 days.

25 μL of Promega CellTiter-Glo reagent was added to each well of the cell plate and incubated at room temperature for 10 minutes to allow the luminescent signal to stabilize. The cells were read using a PerkinElmer Envision Multilabel Analyzer.

Data Analysis:

The raw data were converted to inhibition ratios using the equation (Max-Ratio)/(Max-Min)*100%. IC50 values were then derived by four-parameter curve fitting (derived using the 205 model in XLFIT5, iDBS). Table 1 provides the inhibitory activity of the compounds of the present invention against MCF-7 and MDA-MB-436 cell proliferation.

Experimental conclusion:

The compounds of the present invention have significant inhibitory activity against CDK4 and CDK6 kinases and have high selectivity for CDK2 kinase. Furthermore, the compounds of the present invention have significant proliferation inhibitory activity against estrogen receptor-positive MCF-7 breast cancer cells, but have poor proliferation inhibitory activity against estrogen receptor-negative MDA-MB-436 cells. Examples 3, 9, 10, and 15 have higher CDK4 and CDK6 kinase inhibitory activity than the reference compounds Palbociclib and LY2835219; Examples 3, 7, 9, 10, and 15 have higher MCF-7 cell proliferation inhibitory activity than the reference compounds Palbociclib and LY2835219; and Example 7 has higher selectivity (MCF-7/MDA-MB-436) for proliferation inhibitory activity against estrogen receptor-positive breast cancer cells than the reference compound LY2835219.

Table 1

Caco-2 cell bidirectional permeability evaluation experiment

Purpose of the experiment:

Caco-2 cells are a widely used in vitro model for studying small intestinal absorption. They are human colon cancer cells. The monolayer Caco-2 cell model has been widely used to evaluate passive and active transport processes during small intestinal absorption. GF120918A is a strong inhibitor of efflux transporters, including P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). This experiment was used to determine the bidirectional permeability of Example 7 and the reference compounds Palbociclib and LY2835219 through the Caco-2 cell model, and the efflux transport of the test compounds was evaluated by adding GF120918A.

Experimental operation:

The standard experimental conditions are as follows:

- Test concentration: 2 μM (DMSO ≤ 1%);

- Replicate: n = 2;

- Direction: Bidirectional transport, including A→B and B→A;

- Incubation time: single time point, 2 hours;

-Transport buffer: HBSS, pH 7.4;

-Incubation conditions: 37°C, 5% CO2.

After incubation, sample solutions from the dosing and receiving wells were immediately mixed with cold acetonitrile containing an internal standard. The concentration of the test compound in all samples (including the initial dosing solution, the supernatant from the dosing well, and the receiving solution) was analyzed using LC/MS/MS. Parameters such as the apparent permeability coefficient and efflux ratio were also calculated.

Experimental conclusion:

Table 2 lists the permeability coefficients of Example 7 and reference compounds Palbociclib and LY2835219 in Caco-2 cell monolayers. Compared with the reference compounds Palbociclib and LY2835219, Example 7 has higher permeability and is less likely to be affected by efflux transporters in vivo. This improved permeability may allow Example 7 to be more widely distributed in tissues (such as the breast and lungs) in vivo, resulting in better anti-tumor efficacy in vivo. Furthermore, this improved permeability may enable Example 7 to penetrate the blood-brain barrier, potentially achieving the goal of treating brain metastases of breast cancer or lung cancer.

Table 2

Brain permeability studies

Purpose of the experiment:

SD rats were used as test animals, and the drug concentrations in the brain and plasma at different time points after oral administration of Example 7 and reference compounds Palbociclib and LY2835219 were determined by LC/MS/MS to evaluate their brain tissue distribution characteristics.

Experimental operation:

Twelve healthy adult male Sprague-Dawley rats, aged 7-9 weeks, were purchased from Shanghai Slake Laboratory Animal Co., Ltd. The appropriate amount of test compound was weighed and prepared as a 1 mg/mL suspension in 0.5% methylcellulose. Rats received a single oral dose of 10 mg/kg. Three animals were sacrificed 0.5, 2, 8, and 24 hours after administration. Whole blood and brain tissue were collected. Whole blood was centrifuged (3000 g, 15 minutes, 4°C) to prepare plasma. Brain homogenate samples were prepared by homogenizing with a 1:2 methanol:phosphate buffer solution at a ratio of 5:1. Drug concentrations in each sample were determined by LC/MS/MS, and exposure was estimated by calculating the area under the curve (AUC).

Experimental conclusion:

Table 3 shows brain tissue exposure data for Example 7 of the present invention and the reference compounds Palbociclib and LY2835219 at an oral dose of 10 mg/kg. The results show that at both 0.5 and 2 hours, Example 7 of the present invention had higher brain tissue exposure in rats compared to the reference compounds Palbociclib and LY2835219, suggesting that Example 7 is suitable for development as a drug for treating brain metastases. Furthermore, after 8 hours, the brain exposure of Example 7 of the present invention significantly decreased, falling between that of the reference compounds Palbociclib and LY2835219, indicating that Example 7 does not accumulate in the brain for an extended period of time and has a good safety profile.

Table 3

In vivo efficacy studies

In vivo efficacy studies were performed on BALB/c nude mice subcutaneously implanted with MCF-7 breast cancer patient-derived human tumor cell line xenografts (CDX).

Experimental operation:

BALB/c nude mice, female, 6-8 weeks, weighing about 18-22 grams, were kept in a special pathogen-free environment and in single ventilated cages (10 mice per cage). All cages, bedding and water were disinfected before use. All animals had free access to standard certified commercial laboratory diets. A total of 100 mice purchased from Shanghai BK Laboratory Animal Co., LTD were used for the study. Each mouse was subcutaneously implanted with an estrogen tablet (0.36 gram, 60-day sustained release) in the left flank. After 3 days, each mouse was subcutaneously implanted with tumor cells (10x 10 ⁶ in 0.2 ml of phosphate buffered saline) in the right flank for tumor growth. Dosing began when the average tumor volume reached about 150-200 cubic millimeters. The test compound was orally administered daily, and the dosage was as shown in Table 5. Tumor volume was measured every 3 days using a two-dimensional caliper. Volume was measured in cubic millimeters and calculated using the following formula: V = 0.5 a x ^{b 2} , where a and b are the major and minor diameters of the tumor, respectively. Antitumor efficacy was determined by dividing the mean tumor volume increase in animals treated with the compound by the mean tumor volume increase in untreated animals.

Experimental conclusion:

Examples 3 and 7 of the present invention demonstrated significant antitumor activity in the MCF-7 breast cancer xenograft (CDX) model based on a human tumor cell line. As shown in Table 4, 21 days after the start of the experiment, the tumor volume of the untreated animal group rapidly increased from 187 cubic millimeters to 1443 cubic millimeters, while the tumor volume of the animal group in Example 3 only slowly increased from 187 cubic millimeters to 432 cubic millimeters during the same period, a growth rate significantly slower than that of the reference compounds Palbociclib and LY2835219. Considering that the dosage of Example 3 (25 mg/kg) is only half of the reference compound LY2835219 (50 mg/kg) or nearly half of the reference compound Palbociclib (45 mg/kg) (experiments have shown that high doses of Palbociclib are not tolerated), we believe that the antitumor activity of Example 3 is significantly superior to these two reference compounds. At the same time, 21 days after administration, the tumor volume of the animal group of Example 7 slowly increased from the initial 187 cubic millimeters to 350 cubic millimeters, and the growth rate was significantly slower than that of the group of the reference compound LY2835219 at the same dose. This indicates that compared with the reference compound LY2835219 at the same dose, the anti-tumor activity of Example 7 is more significant.

Table 4

Claims (13)

1. The compound represented by formula (Ⅰ), or a pharmaceutically acceptable salt thereof, in, Selected from _R1 is selected from isopropyl, 2-propenyl, or allyl; _R2 is selected from methyl or phenyl; _R3 is selected from H or halogen; _R4 , _R5 , and _R6 are each independently selected from H, halogen, OH, _NH2 , CN, =O, _C1-8 alkylamino, N,N-di( _C1-8 alkyl)amino, or selected from _C1-8 alkyl groups optionally substituted with 1, 2, or 3 Rs. R ₇ is selected from H or halogen; _X1 , _X2 , and _X3 are each independently selected from C(R ₁₀ ); X ₄ is selected from N or CH; W is selected from a single bond; T is selected from N; Q is selected from N; m and n are each independently selected from 1; R is selected from F, Cl, Br, I, _NH₂ , CN, OH, _CF₃ , _CHF₂ , _CH₂F , _NHCH₃ , N( _CH₃ ) _₂ ; R ₁₀ is selected from H or methyl; Optionally, the structural unit is replaced with 2. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, in, Selected from _R1 is selected from isopropyl, 2-propenyl, or allyl; _R2 is selected from methyl or phenyl; _R3 is selected from H or halogen; _R4 , _R5 , and _R6 are each independently selected from H, halogen, OH, _NH2 , CN, =O, _C1-8 alkylamino, N,N-di( _C1-8 alkyl)amino, or selected from _C1-8 alkyl groups optionally substituted with 1, 2, or 3 Rs. R ₇ is selected from H or halogen; _X1 , _X2 , and _X3 are each independently selected from C(R ₁₀ ); X ₄ is selected from N or CH; W is selected from a single bond; T is selected from N; Q is selected from N; m and n are each independently selected from 1; R is selected from F, Cl, Br, I, _NH₂ , CN, OH, _CF₃ , _CHF₂ , _CH₂F , _NHCH₃ , N( _CH₃ ) _₂ ; R ₁₀ is selected from H or methyl. 3. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R1 is selected from isopropyl. 4. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R2 is selected from methyl. 5. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R3 is selected from F. 6. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R4 is selected from H, halogens, OH, _NH2 , Me, Et, CN, 7. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R5 is selected from H, halogens, OH, _NH2 , ... 8. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein _R6 is selected from H, halogens, OH, _NH2 , ... 9. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein _R7 is selected from H, F, or Cl. 10. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein the structural unit is selected from... 11. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein the structural unit is selected from... 12. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein the structural unit is selected from... 13. Compounds, selected from: Or its pharmaceutically acceptable salt.