TRPV1 antagonists

1. A compound of formula (I)

or a pharmaceutically acceptable salt, wherein

R 1 is a monocyclic heteroaryl, which is optionally substituted with 1, 2, 3, 4, or 5 substituents as represented by R 6 groups;

R 2 is halogen, alkyl, haloalkyl, —CN, —O(alkyl), —O(haloalkyl), —OH, —NH 2 , —N(H)(alkyl), or —N(alkyl) 2 ; or

R 2 and the adjacent carbon atom, together with the carbon atom to which R 2 is attached, form a 3-6 membered monocyclic cycloalkyl ring that is optionally substituted with 1, 2, 3, or 4 substituents independently selected from the group consisting of alkyl, hydroxyalkyl, alkoxyalkyl, haloalkoxyalkyl, haloalkyl, arylalkyl, aryl, aminoalkyl, amino, and halogen, wherein the aryl and the aryl moiety of the arylalkyl are each independently unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen, OH, O(alkyl), O(haloalkyl), amino, and haloalkyl;

R 3 is hydrogen or C 1-6 alkyl;

R 4 is aryl, heteroaryl, cycloalkyl, cycloalkenyl, or heterocycle, wherein each R 4 is optionally substituted with 1, 2, 3, 4, 5, or 6 substituents as represented by R 7 groups;

R 5 represents an optional substituent on the cycloalkene ring, and is haloalkyl, halogen, —OH, —NO 2 , NH 2 , N(H)(alkyl), N(alkyl) 2 , alkyl, alkenyl, alkynyl, or -G 1 ;

X is O;

m is 1;

n is 0 or 1;

R 7 , at each occurrence, is independently alkyl, alkenyl, alkynyl, oxo, —NO 2 , —CN, halogen, -G 2 , —OR a , —OC(O)R a , —SR a , —SF 5 , —S(O)R b , —S(O) 2 R b , —S(O) 2 N(R a )(R c ), —N(R a )(R c ), —N(R c )C(O)R a , —N(R c )S(O) 2 R b , —N(R c )C(O)N(R a )(R c ), —N(R c )S(O) 2 N(R a )(R c ), —C(O)R a , —C(O)O(R a ), —C(O)N(R a )(R c ), haloalkyl, —(CR j R k ) p —CN, —(CR j R k ) p —OR a , —(CR j R k ) p —OC(O)R a , —(CR j R k ) p —SR a , —(CR j R k ) p —S(O)R b , —(CR j R k ) p —S(O) 2 R b , —(CR j R k ) p N(R a )(R c ), —(CR j R k ) p —N(R c )C(O)R a , —(CR j R k ) p —N(R c )S(O) 2 R b , —(CR j R k ) p —N(R c )C(O)N(R a )(R c ), —(CR j R k ) p —N(R c )S(O) 2 N(R a )(R c ), —(CR j R k ) p —C(O)R a , —(CR j R k ) p —C(O)O(R a ), —(CR j R k ) p —C(O)N(R a )(R c ), or —(CR j R k ) p -G 2 ;

R a , at each occurrence, is independently hydrogen, alkyl, haloalkyl, -G 2 , or —(CR u R v ) w -G 2 ;

R b , at each occurrence, is independently alkyl, haloalkyl, -G 2 , or —(CR u R v ) w -G 2 ;

G 1 and G 2 , are each independently aryl, heteroaryl, cycloalkyl, cycloalkenyl, or heterocycle; each of which is independently unsubstituted or substituted with 1, 2, 3, 4, 5, or 6 substituents as represented by R 8 groups;

R 6 , at each occurrence, is independently alkyl, alkenyl, alkynyl, —NO 2 , —CN, halogen, —OR d , —OC(O)R d , —SR d , —S(O)R e , —S(O) 2 R e , —S(O) 2 N(R d )(R f ), —N(R d )(R f ), —N(R f )C(O)R d , —N(R f )S(O) 2 R e , —N(R f )C(O)N(R d )(R f ), —N(R f )S(O) 2 N(R d )(R f ), —C(O)R d , —C(O)O(R d ), —C(O)N(R d )(R f ), haloalkyl, —(CR s R t ) q —CN, —(CR s R t ) q —OR a , —(CR s R t ) q —OC(O)R d —(CR s R t ) q —SR d , —(CR s R t ) q —S(O)R e , —(CR s R t ) q —S(O) 2 R e , —(CR s R t ) q —N(R d )(R f ), —(CR s R t ) q —N(R f )C(O)R d , —(CR s R t ) q —N(R f )S(O) 2 R e , —(CR s R t ) q —N(R f )C(O)N(R d )(R f ), —(CR s R t ) q —N(R f )S(O) 2 N(R d )(R f ), —(CR s R t ) q —C(O)R d , —(CR s R t ) q —C(O)O(R d ), or —(CR s R t ) q —C(O)N(R d )(R f );

R 8 , at each occurrence, is independently alkyl, alkenyl, alkynyl, oxo, —NO 2 , —CN, halogen, —OR d , —OC(O)R d , —SR d , —S(O)R e , —S(O) 2 R e , —S(O) 2 N(R d )(R f ), —N(R d )(R f ), —N(R f )C(O)R d , —N(R f )S(O) 2 R e , —N(R f )C(O)N(R d )(R f ), —N(R f )S(O) 2 N(R d )(R f ), —C(O)R d , —C(O)O(R d ), —C(O)N(R d )(R f ), haloalkyl, —(CR s R t ) q —CN, —(CR s R t ) q —OR a , —(CR s R t ) q —OC(O)R d , —(CR s R t ) q —SR d , —(CR s R t ) q —S(O)R e , —(CR s R t ) q —S(O) 2 R e , —(CR s R t ) q —N(R d )(R f ), —(CR s R t ) q —N(R f )C(O)R d , —(CR s R t ) q —N(R f )S(O) 2 R e , —(CR s R t ) q —N(R f )C(O)N(R d )(R f ), —(CR s R t ) q —N(R f )S(O) 2 N(R d )(R f ), —(CR s R t ) q —C(O)R d , —(CR s R t ) q —C(O)O(R d ), or —(CR s R t ) q —C(O)N(R d )(R f );

R c , R d and R f , at each occurrence, are each independently hydrogen, alkyl, or haloalkyl;

R e , at each occurrence, is independently alkyl or haloalkyl;

R j , R k , R s , R t , R u , and R v , at each occurrence, are each independently hydrogen, halogen, alkyl, or haloalkyl; and

p, q, and w, at each occurrence, are each independently 1, 2, 3, or 4.

2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R 2 is halogen or alkyl.

3. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein the monocyclic heteroaryl is pyridinyl.

4. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R 4 is optionally substituted heteroaryl.

5. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R 4 is optionally substituted phenyl.

6. The compound according to claim 5 or a pharmaceutically acceptable salt thereof, wherein R 2 is halogen or alkyl.

7. The compound according to claim 1 having formula (III), or a pharmaceutically acceptable salt thereof

wherein R 2 , R 5 , R 6 , R 7 , and n are as defined in formula (I).

8. The compound of claim 7 or a pharmaceutically acceptable salt thereof wherein R 2 is halogen or alkyl.

9. The compound of claim 8 or a pharmaceutically acceptable salt thereof wherein n is 0.

10. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, selected from the group consisting of

4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

N-(4-chlorophenyl)-4-(3-chloropyridin-2-yl)-4-fluorocyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)-4-fluorocyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(trifluoromethoxy)phenyl]cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-N-[4-(1-cyano-1-methylethyl)phenyl]-4-fluorocyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-methoxy-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-methoxy-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-methylpyridin-2-yl)-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-methylpyridin-2-yl)-N-[4-(trifluoromethoxy)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-methylpyridin-2-yl)-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

N-(4-chlorophenyl)-4-fluoro-4-(3-methylpyridin-2-yl)cyclohex-1-ene-1-carboxamide;

N-(4-tert-butylphenyl)-4-fluoro-4-(3-methylpyridin-2-yl)cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-fluoropyridin-2-yl)-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

N-(4-tert-butylphenyl)-4-fluoro-4-(3-fluoropyridin-2-yl)cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-fluoropyridin-2-yl)-N-[5-(trifluoromethyl)pyridin-2-yl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-fluoropyridin-2-yl)-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(3-fluoropyridin-2-yl)-N-[4-(pentafluoro-λ 6 -sulfanyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(1,3-thiazol-2-yl)-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(1,3-thiazol-2-yl)-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

(4R)—N-(4-chlorophenyl)-4-(3-chloropyridin-2-yl)-4-fluorocyclohex-1-ene-1-carboxamide;

(4S)—N-(4-chlorophenyl)-4-(3-chloropyridin-2-yl)-4-fluorocyclohex-1-ene-1-carboxamide;

(4R)-4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

(4S)-4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-[3-(dimethylamino)pyridin-2-yl]-4-(trifluoromethyl)-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-fluoro-4-(1,3-thiazol-2-yl)-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

(4R)-4-(3-chloropyridin-2-yl)-4-fluoro-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

(4S)-4-(3-chloropyridin-2-yl)-4-fluoro-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

N-{4-[(difluoromethyl)sulfonyl]phenyl}-4-fluoro-4-(3-fluoropyridin-2-yl)cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(pentafluoro-λ 6 -sulfanyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-6-methyl-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-(trifluoromethyl)-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-N-(4-isopropylphenyl)cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-N-[4-(2,2,2-trifluoro-1-methylethyl)phenyl]cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-fluoro-6-methyl-N-{4-[(trifluoromethyl)sulfonyl]phenyl}cyclohex-1-ene-1-carboxamide;

4-(3-chloropyridin-2-yl)-4-methyl-N-[4-(trifluoromethyl)phenyl]cyclohex-1-ene-1-carboxamide; and

N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)-4-methylcyclohex-1-ene-1-carboxamide.

11. A pharmaceutical composition comprising a therapeutically effective amount of a compound of formula (I) according to claim 1 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

12. The pharmaceutical composition of claim 11 further comprises acetaminophen or one or more nonsteroidal anti-inflammatory drug, or a combination thereof.

13. The pharmaceutical composition of claim 12 wherein the nonsteroidal anti-inflammatory drug is ibuprofen.