NEW HYDROXYNAPHTHYL AMIDES
FIELD OF THE INVENTION
The present invention relates to a new class of compounds, to pharmaceutical formulations containing said compounds and to the use of said compounds in therapy. The present invention further relates to processes for the preparation of said compounds.
BACKGROUND OF THE INVENTION
Pain sensation in mammals is due to the activation of the peripheral terminals of a- . . specialized population of sensory neurons known as nociceptors. Capsaicin, the active ■; ingredient in hot peppers, produces sustained activation of nociceptors and' also produces a' dose-dependent pain sensation in humans. Cloning of the vanilloid receptor 1 (VRl or TRPVl) demonstrated that VRl is the molecular target for capsaicin and its analogues. (Caterina,MJ., Schumacher.M.A., et.al. Nature (1997) v.389 p 816-824). Functional studies using VRi indicate that it is also activated by noxious heat , tissue acidification) and other inflammatory mediators (Tominaga,M., Caterina,M.J. et.al. Neuron (1998) v.21, p.531-543). Expression of VRl is also regulated after peripheral nerve damage of the type that leads to neuropathic pain. These properties of VRl make it a highly relevant target for pain and for diseases involving inflammation. While agonists of the VRl receptor can act as analgesics through nociceptor destruction, the use of agonists, such as capsaicin and its analogues, is limited due to their pungency, neurotoxicity and induction of hypothermia. Instead, agents that block the activity of VRl should prove more useful. Antagonists would maintain the analgesic properties, but avoid pungency and neurotoxicity side effects. Compounds with VRl inhibitor activity are believed to be of potential use for the treatment and/or prophylaxis of disorders such as pain, especially that of inflammatory or traumatic origin such as arthritis, ischaemia, cancer, fibromyalgia, low back pain and post-operative
pain (Walker et al J Pharmacol Exp Ther. (2003) Jan;304(l):56-62). In addition to this visceral pains such as chronic pelvic pain, cystitis, including interstitial cystitis, irritable bowel syndrome (IBS), pancreatitis and the like, as well as neuropathic pain such as sciatia, diabetic neuropathy, HIV neuropathy, multiple sclerosis, and the like (Walker et al ibid, Rashid et al J Pharmacol Exp Ther. (2003) Mar;304(3):940-8), are potential pain states that could be treated with VRl inhibitonThese compounds are also believed to be potentially useful for inflammatory disorders like asthma, cough, inflammatory bowel disease (IBD) (Hwang and Oh Curr Opin Pharmacol (2002) Jun;2(3):235-42). Compounds with VRl blocker activity are also useful for itch and skin diseases like psoriasis and for gastro-esophageal reflux disease (GERD), emesis, cancer, urinary incontinence and. hyperactive bladder (Yiangou et al BJU Int (2001) Jun;87(9):774-9, Szallasi Am J Clin Pathol (2002) 118: 110-21). VRl inhibitors are also of potential use for the treatment and/or prophylaxis of the effects of exposure to VRl activators like capsaicin or tear gas, acids or heat (Szallasi ibid). . : ■ :• . . > A further portential use relates to the treatment of tolerance to VRl activators.
Prior art
There are many properties of a compound that are of importance in determining its suitability as a drug product. Of high importance is the interaction of the compound at the target protein and its pharmacokinetic profile, i.e. its ability to access the target protein in sufficient quantity for a sufficient duration of time to have the desired therapeutic effect.
The object of the present invention is to provide novel hydroxynaphthyl amides-derivatives with surprisingly improved characteristics, carrying other substituents in the amino group at the naphtyl ring as previously described. WO 03/014064 discloses phenyl-naphtyl urea derivatives having a vanilloid receptor antagonistic activity. These compounds differ among others, from the compounds of the present invention in a different substitution pattern at the amino group.
We have found that these substituents on the naphtyl ring have led to improvements with regard to both efficacy and pharmocokinetic profile.
DETAILED DESCRIPTION OF THE INVENTION
The object of the present invention is to provide compounds exhibiting an inhibitory activity at vanilloid receptor 1 (VRl).
The present invention provides a compound of formula I
R1 is H; R2 is CHR7NR8R9, arylCo-ealkyl or heteroarylCo-6alkyl, whereby the aryl and heteroaryl may be fused with a 5 or 6 membered ring and said arylCo-βalkyl or heteroarylCo-6alkyl • may be optionally substituted by one or more A;
R3 is H;
R4 and R5 are independently selected from the group consisting of H, halo, nitro and COR7;
R7 is H or C1-4alkyl;
R8 is H or Cι-4alkyl;
R9 is arylCo-δalkyl substituted by one or more A, or arylCo-6alkyl, which is fused with a 5 or 6 membered ring and said aryl and 5 or 6 membered ring may be optionally substituted by one or more A, or
R8 and R9 form together a 5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which is fused with a 5 or 6 membered ring and said heterocyclic ring and 5 or 6 membered ring may be optionally substituted by one or more A; A is halo, nitro, CHO, CN, OR7, COR14, R14, C^alkyl, C2-6alkenyl, C2-6alkynyl,
C3-6cycloalkylC0-6alkyl, Cι-4haloalkyl, OC1-4haloalkyl, Co-6alkylNR14R15,
OC1-6alkylNR14R15, C02R14, CONR14R15, NR14(CO)R15, O(CO)R14, COR14, SR14,
(SO2)NR14R15, (SO)NR14R15, SO3R14, S02R14, SOR14or a 5 or 6 membered heterocyclic saturated or partially saturated heterocyclic ring containing one or more heteroatoms independently selected from N, O or S; and
R14 and R15 are independently selected from the group consisting of H, C1-4alkyl, heteroarylC0-6alkyl and arylC0-6alkyl; or salts, solvates or solvated salts thereof.
One embodiment of the invention relates to compounds of formula I wherein:
R1 is H; R2 is CHR7NR8R9, arylCo-βalkyl or heteroarylCo-6alkyls whereby the heteroaryl may be fused with a 5 or 6 membered ring and said arylCo-6alkyl or heteroarylCo-6alkyl may be optionally substituted by one or more A;
R3 is H;
R4 and R5 are H; R7 is H or Cι-4alkyl;
R8 is H or Cι-4alkyl;
R9 is arylCo-ealkyl substituted by one or more A, or arylCo-6alkyl, which is fused with a 5 membered ring, or
R8 and R9 form together a 5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which is fused with a 6 membered ring and said heterocyclic ring and 5 or 6 membered ring may be optionally substituted by one or more A;
A is halo, nitro, CHO, CN, OR7, COR14, R14, Cι-6alkyl, C3-6cycloalkylC0-6alkyl,
Cι-4haloalkyl, OCι-4haloalkyl, C0-6alkylNR14R15 or OC1-6alkylNR14R15; and R14 and R15 are independently selected from the group consisting of H, Cι-4alkyl, heteroarylCo-6alkyl and arylCo-δalkyl.
Another embodiment of the invention relates to the compound of formula I, wherein R\ R3, R4, R5 and R7are H.
One embodiment of the invention relates to the compound of formula I wherein A is halo, nitro, OR7, COR14, R14, Cι-6alkyl, C0-6alkylC3-6cycloalkyl, OC1-4haloalkyl or
C0-6alkylNR14R15.
A further embodiment of the invention relates to the compound of formula I wherein: R1 is H; R2 is CHR7NR8R9; and R7 is H or Cι-2alkyl; R8 is H or C1-2alkyl; R9 is arylCo-βalkyl substituted by one or more A, or arylCo-δalkyl, which is fused with a 5 or 6 membered ring and said aryl and 5 or 6 membered ring may be optionally substituted by one or more A, or R8 and R9 form together a 5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which is fused with a 5 or 6 membered ring and said heterocyclic ring and 5 or 6 membered ring may be optionally substituted by*. one or more A.
Another embodiment of the invention relates to the compound of formula I, wherein R8 is H.
A further embodiment of the invention relates to the compound of formula I, wherein
R9 is aryl substituted by one or more A.
In one emodiment of the invention R9 is phenyl substituted by one or more A.
In a further embodiment R9 is phenyl substituted by one or more A, whereby A is independently selected from the group consisting of halo, COR14, C1-4alkyl or C0-6alkylNR14R15.
In another embodiment R14 and R15 are C1-4alkyl. In a further embodiment R14 and R15 are methyl.
In yet another embodiment A is chloro, fluoro, methyl, t-butyl, acetyl and/or dimethylamino.
In yet another embodiment R9 is phenylmethyl substituted by one or more A, whereby A is halo. In one embodiment A is fluoro.
In a further embodiment R9 is arylCo-6alkyl, which is fused with a 5 or 6 membered ring and said aryl and 5 or 6 membered ring may be optionally substituted by one or more A. In another embodiment R9 is phenyl fused with a 5 membered ring.
In yet a further embodiment of the invention R and R form together a 5 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which is fused with a 6 membered ring and said 6 membered ring may be optionally substituted by one A. In one embodiment of the invention R9 and R8 form together a 5 membered heterocyclic ring containing one N atom, which is fused with phenyl and optionally substituted by one A. In another embodiment A is nitro.
One embodiment related to compounds of formula I wherein R2 is fluoromethylphenylamino, dihydroindolyl, indanylamino, (chlorophenyl)methylamino, nitro-dihydro-1-indolyl, (difluorophenyl)methyl]amino, (chlorofluorophenyl)amino, (acetylphenyl)amino, (dimethylamino)phenyl] amino, (butylphenyl)amino, or (difluorophenyl)amino.
Another embodiment of the invention relates to the compound of formula I, wherein R1 is H; R2 is arylCo-6alkyl or heteroarylC0-6alkyl, whereby the aryl or heteroaryl may be fused with a 5 or 6 membered ring and said arylCo-6alkyl or heteroarylCo-βalkyl may be optionally substituted by one or more A.
In one embodiment R is arylCι-3alkyl optionally substituted by one or more A. 7
In another embodiment R is arylCι-3alkyl substituted by one or more OR , C3-6cycloalkyl or phenyl. 7
In a further embodiment R is phenylmethyl substituted by one or more OR , C3-6cycloalkyl or phenyl.
In yet another embodiment R2 is aryl optionally substituted by one or more A. In yet a further embodiment R2 is phenyl optionally substituted by one or more A.
In one embodiment R2 is phenyl substituted by one or more COR14, wherein R14is aryl.
In another embodiment R2 is phenyl substituted by one or more R14, wherein R14 is heteroarylC0-6alkyl containing one N atom.
In a further embodiment R2 is phenyl substituted by one or more R14, wherein R14is imidazole or pyrolle.
In yet another embodiment R2 is phenyl substituted by one or more OR7 wherein R7 is .
4alkyl.
In yet a further embodiment R2 is phenyl substituted by one or more OC1-2haloalkyl.
In one embodiment R2 is heteroaryl which is fused with a 6 membered ring and said heteroaryl may be optionally substituted by one or more A. In another embodiment R2 is heteroaryl which is fused phenyl.
One embodiment related to compounds of formula I wherein R2 is imidazolyl-benzamide, (methoxyphenyl)-cyclopropanecarboxylic acid, diphenyl, benzo[b]thiophene-2-carboxylic acid, benzoyl, trifluoromethoxy-benzamide or pyrrolyl- benzamide.
Another embodiment of the invention relates to compounds selected from the group 2-[(3-fluoro-4-methylphenyl)amino]-N-(7-hydroxy- 1 -naphthyl)-acetamide, 2-[(2,3-Dihydroindol- 1 -yl)]-N-(7-hydroxy- 1 -naphthyl)-acetamide, N-(7-Hydroxy- 1 -naphthyl)-2-(indan-5-ylamino)-acetamide, 2-[(4-cMorophenyl)methylamino]-N-(7-hydroxy-l-naphthyl)-acetamide, 2- [(5-nitro-2,3-dihydro- 1 -indolyl)]-N-(7-hydroxy- 1 -naphthyl)-acetamide, 2-[[(3,4-difluorophenyl)methyl]amino]-N-(7-hydroxy-l-naphthyl)-acetamide, 2-[(3-chloro-4-fluorophenyl)amino]-N-(7-hydroxy-l-naphthyl)-acetamide, 2-[(3-acetylphenyl)amino]-N-(7-hydroxy-l-naphthyl)-acetamide, 2-[[3-(dimethylamino)phenyl]amino]-N-(7-hydroxy-l-naphthyl)-acetamide, 2-[[4-t-butylphenyl]amino]-N-(7-hydroxy-l-naphthyl)-acetamide, and 2-[(3,4-difluorophenyl)amino]-N-(7-hydroxy-l-naphthyl)-acetamide, or salts, solvates or solvated salts thereof.
A further embodiment of the invention relates to compounds selected from the group consisting of N-(7-hydroxy- 1 -naphthyl)-2-(2-methoxyphenyl)-acetamide,
N-(7-hydroxy-l-naphthyl)-4-imidazol-l-yl-benzamide, l-(4-methoxyphenyl)-cyclopropanecarboxylic acid (7-hydroxy-l-naphthyl)-amide, N-(7-hydroxy- 1 -naphthyl)-2,2-diphenyl-acetamide, benzo[b]thiophene-2-carboxylic acid (7-hydroxy-l-naphthyl)-amide,
4-benzoyl-N-(7-hydroxy- 1 -naphthyl)-benzamide,
N-(7-Hydroxy- 1 -naphthyl)-4-trifluoromethoxy-benzamide, and
N-(7-Hydroxy- 1 -naphthyl)-4-pyrrol- 1 -yl-benzamide, or salts, solvates or solvated salts thereof.
Yet a further embodiment of the invention relates to the compound (7-hydroxy-l- naphthyl)-carbamic acid 4-methoxybenzyl ester, or salts, solvates or solvated salts thereof.
Another embodiment of the invention relates to compounds of formula I wherein:
R1 is H when R2 is OR6, CHR7NR8R9, arylCo-6alkyl or heteroarylC0-6alkyl, whereby the aryl may be fused with a 5 or 6 membered ring and said arylC0-6alkyl or heteroarylC0-6alkyl may be optionally substituted by one or more A;
R3 is H; R and R are independently selected from the group consisting of H, halo, nitro and
COR7;
R is H or arylCo-6alkyl optionally substituted by one or more A;
R and R are independently selected from the group consisting of H, C1-4alkyl, arylCo- 6alkyl, heteroarylCo-6alkyl and a 5 or 6 membered saturated or partially saturated heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, whereby the aryl or heterocyclic ring may be fused with a 5 or 6 membered ring and said aryl and 5 or 6 membered ring may be optionally substituted by one or more A, or R and R form together a 5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which may be fused with a 5 or 6 membered ring and said heterocyclic ring and 5 or 6 membered ring may be optionally substituted by one or more A; R7, R14 and R15 are independently selected from the group consisting of H,
Cι- alkyl, heteroarylC0-6alkyl and arylC0-6alkyl, whereby any aryl or heteroaryl may be substituted by one or more A; or
R14 and R15 are C1- alkyl and form together a ring; and
A is halo, nitro, CHO, CN, OR7, COR14, R14, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C0.6alkylC3-6cycloalkyl, C1-4haloalkyl, OC1-4haloalkyl, C0-6alkylNR14R15,
OCι-6alkylNR14R15, CO2R14, CONR14R15, NR14(CO)R15, O(CO)R14, COR14, SR14,
(SO2)NR14R15, (SO)NR14R15, SO3R14, SO2R14, SOR14or a 5 or 6 membered heterocyclic saturated or partially saturated heterocyclic ring containing one or more heteroatoms independently selected from N, O or S; or salts, solvates or solvated salts thereof.
Listed below are definitions of various terms used in the specification and claims to illustrate the present invention.
For the avoidance of doubt it is to be understood that where in this specification a group is qualified by 'hereinbefore'defined5, .'defined hereinbefore' or 'defined above' the said group encompasses the first occurring and broadest definition as well as each and all of the other definitions for that group.
For the avoidance of doubt it is to be understood that in this specification 'Cι-6' means a carbon group having 1, 2, 3, 4, 5 or 6 carbon atoms.
In this specification, unless stated otherwise, the term "alkyl" includes both straight and branched chain alkyl groups and may be, but are not limited to methyl, ethyl, n-propyl, i- propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, i-pentyl, t-pentyl, neo-pentyl, n-hexyl, i- hexyl or t-hexyl. The term Cι-3alkyl having 1 to 3 carbon atoms may be methyl, ethyl, n- propyl or i-propyl.
In this specification, unless stated otherwise, the term "cycloalkyl" refers to an optionally substituted, saturated cyclic hydrocarbon ring system. The term "C3-7cycloalkyl" may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl.
In this specification, unless stated otherwise, the term "alkenyl" includes both straight and branched chain alkenyl groups. The term C2-6alkenyl having 2 to 6 carbon atoms and one or two double bonds, may be, but is not limited to vinyl, allyl, propenyl, butenyl, crotyl, pentenyl, or hexenyl. A butenyl group may for example be, buten-2-yl, buten-3-yl or buten-4-yl.
In this specification, unless stated otherwise, the term "alkynyl" includes both straight and branched chain alkynyl groups. The term C2-6alkynyl having 2 to 6 carbon atoms and one or two trippel bonds, may be, but is not limited to etynyl, propargyl, pentynyl or hexynyl. A butynyl group may for example be, butyn-3-yl or butyn-4-yl.
In this specification, unless stated otherwise, the terms "aryl" and "heteroaryl" refer to an optionally substituted monocyclic hydrocarbon unsaturated aromatic ring system. Examples of "aryl" may be, but are not limited to, phenyl or naphthalenyl. Examples of "heteroaryl" may be, but are not limited to, furan, thiophene, pyrrole, triazole, pyrazole, pyridazine, pyrimidine, pyrazine, triazine or pyran.
In this specification, unless stated otherwise, the terms "arylalkyl" and "heteroarylalkyl" refer to a substituent that is attached via the alkyl to an aryl group.
In this specification, unless stated otherwise, the term "5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S" includes both heteroaromatic rings and heterocyclic rings that are saturated or unsaturated. Examples of such heterocyclic rings may be, but is not limited to imidazolidinyl, morpholinyl, piperazinyl, piperidyl, piperidonyl, pyrazolidinyl, pyrrolidinyl or tetrahydropyranyl.
In this specification, unless stated otherwise, the term "5 or 6 membered saturated or partially saturated heterocyclic ring containing one or more heteroatoms independently selected from N, O or S," may be, but is not limited to morpholinyl, piperazinyl, piperidyl, piperidonyl, pyrazolidinyl, pyrrolidinyl or tetrahydropyranyl.
In this specification, unless stated otherwise, the terms "5 or 6 membered ring" includes both aromatic, heteroaromatic rings and heterocyclic rings that are saturated or unsaturated. Examples of such rings may be, but are not limited to, cyclopentyl, cyclohexyl, furyl, thiophenyl, pyrollyl, pyrolinyl, pyrrolidinyl, oxazolyl, thiazolyl, imidazolyl, imidazolinyl, pyrazolyl, pyryl, pyridinyl, piperidinyl, morpholinyl, pyrimidinyl, pyridazinyl or pyrazinyl.
In this specification, unless stated otherwise, the terms "5, 6 or 7 membered heterocyclic ring containing one or more heteroatoms independently selected from N, O or S, which is fused with a 5 or 6 membered ring", or "aryl or heteroaryl which is fused with a 5 or 6 membered ring" includes both aromatic, heteroaromatic rings and heterocyclic rings that are saturated or unsaturated. Examples of such rings may be, but are not limited to, indoline, indole, indolizine, isoindole, benzofuran, benzothiophene, indazole, benzimidazole, benzothiazole, purine, quinoline, quinolizine, isoquinoline, quinozoline, quinoxaline, naphthalene, indene, azulene, oxindole, cinnoline, chroman or isochroman. -
In this specification, unless stated otherwise, the terms "halo" and "halogen" may be fluoro, iodo, chloro or bromo.
In this specification, unless stated otherwise, the term "haloalkyl" refers to an alkyl group as defined above, which is substituted with halo. The term "C1-6haloalkyl" may be, but is not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl, difluoroethyl or bromopropyl. The term "OCι-4haloalkyl" may be, but is not limited to, fluoromethoxy, difluoromethoxy, trifluoromethoxy, fluoroethoxy or difluoroethoxy.
The present invention relates to the use of compounds of formula I as hereinbefore defined as well as to the salts, solvates or solvated salts thereof. Salts for use in pharmaceutical formulations will be pharmaceutically acceptable salts, but other salts may be useful in the production of the compounds of formula I. A suitable pharmaceutically acceptable salt of the compounds of the invention is, for example, an acid-addition salt, for example an inorganic or organic acid salt. In addition, a suitable pharmaceutically acceptable salt of the compounds of the invention is an alkali
metal salt, an alkaline earth metal salt or a salt with an organic base.
Other pharmaceutically acceptable salts and methods of preparing these salts may be found in, for example, Remington's Pharmaceutical Sciences (18th Edition, Mack Publishing Co.,
(1990)).
Some compounds of formula I may have chiral centres and/or geometric isomeric centres (E- and Z- isomers), and it is to be understood that the invention encompasses all such optical, diastereoisomeric and geometric isomers.
The invention also relates to any and all tautomeric forms of the compounds of formula I. .
Methods of Preparation
Another aspect of the present invention provides processes for preparing compounds of formula I, or salts, solvates or solvated salts thereof. .. . , " •
Throughout the following description of such processes it is to be understood that, where appropriate, suitable protecting groups will be added to, and subsequently removed from, the various reactants and intermediates in a manner that will be readily understood by one skilled in the art of organic synthesis. Conventional procedures for using such protecting groups as well as examples of suitable protecting groups are described, for example, in "Protective Groups in Organic Synthesis", T.W. Green, P.G.M. Wuts, Wiley-Interscience, New York, (1999). References and descriptions of other suitable reactions are described in textbooks of organic chemistry, for example, "Advanced Organic Chemistry", March 4th ed. McGraw Hill (1992) or "Organic Synthesis", Smith, McGraw Hill, (1994) The term "room temperature" shall mean, unless otherwise specified, a temperature between 16 and 25 °C.
Another embodiment of the invention relates to processes for the preparation of compounds of formula I according to Method A to C, wherein R1 to R15, unless otherwise specified, are defined as in formula I, comprising;
Method A
whereby the carbamate of formula la is obtained from the isocyanate of formula II and an appropriate alcohol such as the compound of formula Dl.
This reaction may be performed in any manner known to the skilled man in the art. Suitable solvents to be used for this reaction may be halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane or amides such as dimethylformamide and dimethylacetamide or aromatic and heteroaromatic compounds such as benzene, toluene, xylene, pyridine and lutidine of ethers such as ethyl ether, tetrahydrofuran and ., dioxan or any mixtures thereof. '" ■ ι - .
Catalysts such as heteroaromatic bases like pyridine and lutidine or tertiary amines like triethylamine, N-methylmorpholine and ethyl diisopropylamine may be used as well. The temperature may be between 0 and 80°C and the reaction time between 1 and 30 h. Or, Method B
(V) (VI) (Vll)=(lb) wherein R8 and R9 are as defined hereinbefore, comprising a conversion of 8-amino-2- naphthol (V) into the bromacetyl derivative of formula VI following by the amination with an appropriate amine ΝR8R9 to obtain the compound of formula VII. The reaction corresponding to the first step may be performed in any manner known to the skilled man in the art. Suitable solvents to be used for this reaction may be halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane, or aromatic and
heteroaromatic compounds such as benzene, toluene, xylene, pyridine and lutidine or ethers such as ethyl ether, tetrahydrofuran and dioxan or mixtures thereof.
Catalysts such as tertiary amines like triethylamine, N-methylmorpholine and ethyl diisopropylamine may also be used.
The temperature may be between -40 and 20°C and the reaction time between 0.3 and 30 h.
Suitable solvents to be used in the second step may be halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane or amides such as dimethylformamide and dimethylacetamide or aromatic and heteroaromatic compounds such as benzene, toluene, xylene, pyridine and lutidine or ethers such as ethyl ether, tetrahydrofuran and dioxin or alcohols such as methanol, ethanol, isopropanol, n-butanol, and the like or mixtures thereof.
Catalysts such as tertiary amines like triethylamine, N-methylmorpholine and ethyl diisopropylamine may also be used.
The temperature may be between 2,0 and 120°C and the reaction time between 1 and 40 h. .
Or,
Method C
(V) (VIII) (IX)=(ld) wherein R is defined as hereinbefore, and whereby 8-amino-2-naphthol (V) is treated with an acid of formula VIII in the presence of for example l-[3-(dimethylamino)propyl]-3- ethylcarbodiimide hydrochloride and 4-(dimethylamino)-pyridine to obtain a compound of formula LX. This. reaction may suitably be performed in any manner known to the skilled man in the art. The reaction may be carried out in a solvent including halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane or amides such as dimethylformamide and dimethylacetamide or aromatic and heteroaromatic compounds such as benzene, toluene, xylene, pyridine and lutidine or ethers such as ethyl ether, tetrahydrofuran and dioxan. The temperature may be between 0 and 50°C and the reaction time between 1 and 40 h.
Pharmaceutical composition
According to one embodiment of the present invention there is provided a pharmaceutical composition comprising as active ingredient a therapeutically effective amount of the compound of formula I, or salts, solvates or solvated salts thereof, in association with one or more pharmaceutically acceptable diluents, excipients and/or inert carriers.
The composition may be in a form suitable for oral administration, for example as a tablet, pill, syrup, powder, granule or capsule, for parenteral injection (including intravenous, subcutaneous, intramuscular, intravascular or infusion) as a sterile solution, suspension or emulsion, for topical administration e.g. as an ointment, patch or cream or for rectal administration e.g. as a suppository. In general the above compositions may be prepared in a conventional manner using one or more conventional excipients, pharmaceutical acceptable diluents and/or inert carriers.
Suitable daily doses of the compounds of formula I in the treatment of a mammal, including man, are approximately 0.01 to 250 mg/kg bodyweight at peroral administration and about 0.001 to 250 mg kg bodyweight at parenteral administration.
The typical daily dose of the active ingredient varies within a wide range and will depend on various factors such as the relevant indication, severity of the illness being treated, the route of administration, the age, weight and sex of the patient and the particular compound being used, and may be determined by a physician.
Examples of pharmaceutical composition
The following illustrate representative pharmaceutical dosage forms containing a compound of formula I, or salts, solvates or solvated salts thereof, (hereafter compound X), for preventive or therapeutic use in mammals:
The above compositions may be obtained by conventional procedures well known in the pharmaceutical art.
Medical use
Surprisingly, it has been found that the compounds according to the present invention are useful in therapy. The compounds of formula I, or salts, solvates or solvated salts thereof, as well as their corresponding active metabolites, exhibit a high degree of potency and selectivity for individual vanilloid receptor 1 (VRl) groups. Accordingly, the compounds
of the present invention are expected to be useful in the treatment of conditions associated with excitatory activation of vanilloid receptor 1 (VRl).
The compounds may be used to produce an inhibitory effect of VRl in mammals, including man. VRl are highly expressed the peripheral nervous system and in other tissues. Thus, it is expected that the compounds of the invention are well suited for the treatment of VRl mediated disorders.
The compounds of formula I are expected to be suitable for the treatment of acute and chronic pain, acute and chronic neuropathic, pain and acute and chronic inflammatory pain.
Examples of such disorder may be selected from the group comprising arthritis, fibromyalgia, low back pain, post-operative pain, visceral pains like chronic pelvic pain, cystitis, including interstitial cystitis, bowel syndrome (IBS), pancreatitis, ischeamic, sciatia, diabetic neuropathy, multiple sclerosis, HIV neuropathy, asthma, cough and inflammatory bowel disease (IBD).
Further relevant disorders may be selected from the group comprising gastro-esophageal reflux disease (GERD), psoriasis, cancer, emesis, urinary incontinence and hyperactive bladder. Other relevant disorders are related to respiratory diseases and may be selected from the group comprising asthma, chronic obstructive lung disease and emphysema, lung fibrosis and interstitial lung disease.
The VRl inhibitor(s) may be administrated by either an oral or inhaled route. The respiratory disease may be an acute and chronic illness and may be related to infection(s) and/or exposure to environmental pollution and/or irritants.
The compounds of formula I may also be used as antitoxin to treat (over-) exposure to VRl activators like capsaicin, tear gas, acids or heat. Regarding heat, there is a potential use for VRl antagonists in (sun-) burn induced pain, or inflammatory pain resulting from bran injuries. The compounds may further be used for treatment of tolerance to VRl activators.
One embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, in therapy.
Another embodiment of the invention relates to the use of the compounds of formula I as 5 hereinbefore defined, for treatment of VRl mediated disorders.
A further embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, for treatment of acute and chronic pain disorders.
ID Yet another embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, for treatment of acute and chronic neuropathic pain.
Yet a further embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, for treatment of acute and chronic inflammatory pain. J
15 . 7 ■:■
One embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, for treatment of arthritis, fibromyalgia, low back pain, post-operative pain, visceral pains like chronic pelvic pain, cystitis, IBS, pancreatitis or ischeamic.
20 Another embodiment of the invention relates to the use of the compounds of formula I as hereinbefore defined, for treatment of sciatia, diabetic neuropathy, multiple sclerosis or HIV neuropathy.
A further embodiment of the invention relates to the use of the compounds of formula I as 25 hereinbefore defined, for treatment of asthma, cough, IBD, psoriasis, gastro-esophageal reflux disease (GERD), psoriasis, cancer, emesis, urinary incontinence or hyperactive bladder.
Yet another embodiment of the invention relates to the use of the compounds of formula I 30 as hereinbefore defined, for treatment of interstitial cystitis and pain related to interstitial cystitis.
Yet a further embodiment of the invention relates to the use of the compound of formula I as hereinbefore defined, for the treatment of respiratory diseases selected from the group comprising asthma, chronic obstructive lung disease and emphysema, lung fibrosis and interstitial lung disease.
One embodiment of the invention relates to the use of the compound of formula I as hereinbefore defined, in the manufacture of a medicament for treatment of VRl mediated disorders and for treatment of acute and chronic pain disorders, acute and chronic neuropathic pain and acute and chronic inflammatory pain and any other disorder mentioned above.
Another embodiment of the invention relates to a method of treatment of VRl mediated disorders and acute and chronic pain disorders, acute and chronic neuropathic pain and acute and chronic inflammatory pain and any other disorder mentioned above, comprising administrering to a mammal, including man in need of such treatment, a therapeutically. ' effective amount of the compounds of formula I, as hereinbefore defined.
A further embodiment of the invention relates to a pharmaceutical composition comprising a compound of formula I as hereinbefore defined, for use in treatment of VRl mediated disorders and for treatment of acute and chronic pain disorders, acute and chronic neuropathic pain and acute and chronic inflammatory pain and any other disorder mentioned above.
In the context of the present specification, the term "therapy" and "treatment" includes prevention and prophylaxis, unless there are specific indications to the contrary. The terms "treat", "therapeutic" and "therapeutically" should be construed accordingly.
In this specification, unless stated otherwise, the term "inhibitor" and "antagonist" mean a compound that by any means, partly or completely, blocks the transduction pathway leading to the production of a response by the ligand.
The term "disorder", unless stated otherwise, means any condition and disease associated with vanilloid receptor activity.
Non- Medical use
In addition to their use in therapeutic medicine, the compounds of formula I, or salts, solvates or solvated salts thereof, are also useful as pharmacological tools in the development and standardisation of in vitro and in vivo test systems for the evaluation of the effects of inhibitors of VRl related activity in laboratory animals such as cats, dogs, rabbits, monkeys, rats and mice, as part of the search for new therapeutics agents.
Examples
.The invention will now be illustrated by the following non-limiting examples. ; •;■). ' ' .' ..' . . '
General methods • ■.."
All starting materials are commercially available or earlier described in the literature. The !H NMR spectra were recorded on Brucker at 400 MHz. The mass spectra were recorded utilising electrospray (LC-MS; LC: Waters 2790, column XTerra MS C8 2.5 μm 2.1X30 mm, buffer gradient H2O+0.1 %TFA:CH3CN+0.04%TFA, MS : micromass ZMD// ammonium acetate buffer) ionisation techniques.
Example 1
(7-Hydrox -l-naphthyl)-carbamic acid 4-methoxybenzyl ester To a solution of 4-methoxybenzyl alcohol (447 mg, 3.2 mmol) in dichloromethane (3 ml) a solution of 7-hydroxy-l-naphthyl isocyanate (200 mg, 1.1 mmol) in a mixture of dichloromethane and pyridine (1+1 ml) was added at room temperature. The mixture was stirred for 5 h, concentrated in vacuo. The residue was chromatographed on a short column packed with silica gel, using a mixture of hexane and ethyl acetate as an eluent to yield the title product (260 mg, 74%). MW (calcd) 323.35, MW (found) [M+l]: 324; IH NMR (400 MHz, DMSO-d6) δ ppm 3.75 (s, 3H), 5.08 (s, 2H), 6.95 (d, J=8.6 Hz, 2H), 7.08 (dd, J=2.2,
8.7 Hz, IH), 7.22 (t, J=8.1 Hz, IH), 7.25 (d, J=2.0 Hz, IH), 7.34-7.44 (m, 3H), 7.62 (d, J=8.1 Hz, IH), 7.76 (d, J=8.6 Hz, IH), 9.33 (s, IH), 9.72 (br.s, IH).
Example 2 2-[(3-fluoro-4-methylphenyl)amino]-N-(7-hydroxy-l-naphthyl)-acetamide
Bromoacetyl bromide (0.6 mmol, 53 μl) was added under stirring to a solution of 8-amino- 2-naphthol (0.6 mmol, 95 mg in 10 ml dioxane) at 4°C. Triethylamine (0.55 mmol, 56 mg) was added and the reaction stirred at room temperature for 1 h. Solvent was evaporated and the crude 2-Bromo-N-(7-hydroxy-l-naphfhyl)-acetamide obtained was used in Examples 2 tol2 without further purification. MW (calcd) 280.1, MW. (found) [M+l]: 281.1, 281.9 2-Bromo-N-(7-hydroxy-naphthalen-l-yl)-acetamide (56 mg, 0.2 mmol) and triethylamine (0.18 mmol, 26 μl) dissolved in MeOH (3 ml) were added to 3-fluoro-4-methyl- phenylamine (0.3 mmol, 38 mg) at room temperature. The reaction mixture was refluxed for 15 h. The volatiles were removed in vacua and the residue was purified on, a preparative HPLC (XTerra C8 column 19*100 mm, CH CΝ/H20). After concentration of the eluate, the residue was dissolved in EtOAc. The organic phase was washed with water, brine, and dried over Na2SO . Evaporation of the solvent afforded the title compound (38 mg, 60 %). MW (calcd) 324.36, MW (found) [M+l]: 325; IH NMR (400 MHz, acetone) δ ppm 2.1 (s, 3H), 3.98 (s, 2H), 5.68 (s, IH), 6.44 (d, J=7.1 Hz, 2H), 6.46 (s, IH) 6.95 (t, J=8.6 Hz, 1 H), 7.09 (dd, J=2.3, 8.8, Hz, IH) 7.18 (m, 2H) 7.55 (d, J=8.1 Hz, IH) 7.70 (d, J=8.6 Hz, IH) 7.79 (d, J=7.1 Hz, IH) 9.19 (s, IH).
Example 3
2-[(2,3-Dihydroindol-l-yl)]-N-(7-hydroxy-l-naphthyl)-acetamide The title compound was synthesized from 2-bromo-N-(7-hydroxy-l-naphthyl)-acetamide and 2,3-dihydro-lH-indole according to a procedure described in Example 1. Yield 98%. MW (calcd.): 318.38, MW (found) [M+l]: 319; 1Η ΝMR (400 MHz, acetone) δ ppm 3.06 (t, 7=8.1 Hz, 2H), 3.61 (q, 7=8.6 Hz, 2H), 3.88 (s, 2 H), 6.62 (d, 7=7.6 Hz, IH), 6.71 (t, 7=7.3 Hz, IH), 7.06 (m, 4H), 7.21 (t, 7=7.8 Hz, IH), 7.54 (d, 7=8.1 Hz, IH), 7.67 (d, 7=8.6 Hz, IH), 7.86 (d, 7=7.6 Hz, IH), 8.49 (s, 1 H), 9.26 (s, IH).
Example 4
N-(7-Hydroxy-l-naphthyl)-2-(indan-5-ylamino)-acetamide
The title compound was synthesized from 2-bromo-N-(7-hydroxy-l-naphthyl)-acetamide and 4-aminoindan according to a procedure described in Example 1. Yield 55%. MW (calcd.): 332.41, MW (found) [M+l]: 333.0; IH ΝMR (400 MHz, DMSO-d6) δ ppm 1.88- 1.99 (m, 2H), 2.70 (br.t, J=7.2 Hz, 2H), 2.76 (br.t, J=7.3 Hz, 2H), 3.92 (d, J=6.1 Hz, 2H), 5.84-5.89 (m, IH), 6.47 (d, J=7.6 Hz, IH), 6.58 (s, IH), 6.97 (d, J=8.1 Hz, IH), 7.09 (dd, J=2.2, 8.7 Hz, IH), 7.16 (br.s, IH), 7.22 (t, J=7.7 Hz, IH), 7.56 (d, J=7.6 Hz, IH), 7.61 (d, J=8.1 Hz, IH), 7.76 (d, J=8.6 Hz, IH), 9.71 (s, IH), 9.78 (br.s, IH).
10
Examples 5-12
The following compounds were synthesized according to the procedure described in '' '"•- Example 1 starting from 2-bromo-N-(7-hydroxy-l-naphthyl)-acetamide. and. a us Corresponding amine (Table 1). ' ". '
Table 1.
N-(7-hydroxy-l-naphthyl)-2-(2-methoxyphenyl)-acetamide
2-Methoxyphenyl acetic acid (0.1 mmol) was dissolved in dimethylformamide (1 ml). A solution of l-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (0.1 mmol), 4- (dimethylamino)-pyridine (0.1 mmol) and 8-amino-2-naphthol (0.06 mmol) in a mixture of dimethylformamide (0.5 ml) and dichloroethane (0.5 ml) was prepared and added to the solution of the acid. After the mixture was stirred for 18 h, the solvents were removed by evaporation under reduced pressure. The residue was dissolved in ethyl acetate (1 ml) and washed with 1 N sodium hydroxide (1 ml) followed by 1 N hydrochloric acid (1 ml). The organic phase was reduced to dryness by evaporation, under reduced pressure to yield the product. MW found [M+l]: 308.
Examples 14-20
The following compounds, were synthesized according to the procedure described in Example 13 starting from 8-amino-2-naphthol and a corresponding acid (Table 2). Table 2.
Pharmacology
1. hVRl FLIPR (Fluorometric Image Plate Reader) screening assay
Transfected CHO cells, stably expessing hVRl (15,000 cells/well) are seeded in 50 ul media in a black clear bottom 384 plate (Greiner) and grown in a humidified incubator (37°C, 2% C02), 24-30 hours prior to experiment.
Subsequently, the media is removed from the cell plate by inversion and 2 μM Fluo-4 is added using a multidrop (Labsystems). Following the 40 minutes dye incubation in the dark at 37°C and 2% C02, the extracellular dye present is washed away using an EMBLA (Scatron), leaving the cells in 40ul of assay buffer (1 X HBSS, 10 mM D-Glucose, 1 mM CaCl2 , 10 mM HEPES, 10 X 7.5% NaHCO3 and 2.5 mM Probenecid).
FLIPR assay - IC50 determination protocol
For IC50 determinations the fluorescence is read using FLIPR filter 1 (em 520-545 nM). A cellular baseline recording is taken for 30 seconds, followed by a 20 μl addition of 10, titrated half-log concentrations of the test compound, yielding cellular concentration ranging from 3 μM to 0.1 nM. Data is collected every 2 seconds for a further 5 minutes prior to the addition of a VRl agonist solution: either 50 nM solution of capsaicin or MES (2-[N-morpholino] ethanesulfonic acid) buffer (pH 5.2), by the FLIPR pipettor. The FLIPR continues to collect data for a further 4 'minutes. Compounds having antagonistic. properties against the h VRl will inhibit the increase in intracellular calcium in response to the capsaicin addition. This consequently leading to a reduction in fluorescence signal and providing a reduced fluorescence reading, compared with no compound, buffer controls. Data is exported by the FLIPR program as a sum of fluorescence calculated under the curve upon the addition of capsaicin. Maximum inhibition, Hill slope and IC50 data for each compound are generated.
2. DRGs were dissected out from adult Sprague Dawley rats (100-300 g), and placed on ice in L15 Leibovitz medium. The ganglia were enzyme treated with Collagenase 80 U/ml + Dispase 34 U/ml dissolved in DMEM + 5% serum, over night at 37 °C. The next day, cells were triturated with fire polished pasteur pipettes, and seeded in the center of 58 mm diameter Nunc cell dishes coated with Poly-D Lysine (1 mg/ml). The DRGs were cultured in a defined medium without foetal bovine serum, containing Dulbecco's MEM / NUT MIX F- 12 (1:1) without L-glutamine but with pyridoxine, 6 mg/ml D(+)-Glucose, 100 μg/ml apo-transferrin, 1 mg/ml BSA, 20 μg/ml insulin, 2 mM L-glutamine, 50 IU/ ml Penicillin, 50 μg/ml Streptomycin and 0.01 μg/ml NGF-7S.
When the cells had grown for 2 days up to 4 weeks, the experiments were done. Cells were chosen based on size and presence of neurites. Small cells with long processes were used for recording (most likely to be C neurons, with native VRl receptors).
The cells were recorded with conventional whole cell voltage clamp patch clamp, using the following solutions (calcium ion free); extracellular solution (in mM): NaCl 137, KCl 5, MgCl2 * H2O 1.2, HEPES 10, glucose
10, EGTA 5, sucrose 50, pH to 7.4 with NaOH; intracellular solution (in mM): K-gluconate 140, NaCl 3, MgCl2 * H2O 1.2, HEPES 10, EGTA 1 , pH to 7.2 with KOH.
When the cells were penetrated with suction, a puff of capsaicin (500 nM) was used to determine if the cell expressed VRl receptor. If not, a new cell was chosen. If yes, then the compounds were added in increasing doses before the capsaicin pulse (500 nM), to determine the IC50 value.
Results
Typical IC5o values as measured in the assays described above are 10 μM or less. In one embodiment of the invention the IC50 is below 500 nM. In another embodiment of the invention the IC50 is below 100 nM. In a further embodiment of the invention the IC50 is below 10 nM.
Abbreviations
FLIPR Fluorometric Image Plate Reader
HEPES 4-(2-Hydroxyethyl)piperazine-l -ethanesulfonic acid
MES 2-[N-morpholino] ethanesulfonic acid
VRl vanilloid receptor 1
IBS irritable bowel syndrome
IBD inflammatory bowel disease
GERD gastro-esophageal reflux disease
DRG Dorsal Root Ganglion BSA Bovine Serum Albumin
EGTA Ethylene glycol-bis(2-aminoethylemer)-NNN',N'-tetraacetic acid
DMEM Dulbeccos Modified Eagle's Medium