TRPV1 antagonists

1. A method of treating pain, comprising administering a therapeutically effective amount of a compound of formula (III-A):

or a pharmaceutically acceptable salt thereof, to a subject in need thereof, wherein:

R 2 is halogen;

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 c , —(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 method of claim 1 wherein R 6 , at each occurrence, is independently halogen, alkyl, or haloalkyl.

3. The method of claim 1 wherein R 2 is fluoro.

4. The method of claim 1 wherein the compound, or pharmaceutically acceptable salt thereof, is 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-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-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-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;

and pharmaceutically acceptable salts thereof.

5. The method of claim 1 further comprising the step of co-administering with acetaminophen, or with one or more nonsteroidal anti-inflammatory drug, or a combination thereof.

6. The method of claim 1 wherein the nonsteroidal anti-inflammatory drug is ibuprofen.