Compounds as cannabinoid receptor ligands

1. A compound according to formula (I),

or a pharmaceutically acceptable salt thereof, wherein

A is C(R 2 );

E is C(O) or C(S);

R 1 is C 3 -C 7 alkyl, alkenyl, alkoxy-(C 2 -C 6 alkylene)-, alkoxycarbonylalkyl, alkylcarbonylalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkylthioalkyl, alkynyl, aryloxy-(C 2 -C 6 alkylene)-, arylalkoxy-(C 2 -C 6 alkylene)-, arylcarbonyloxy-(C 2 -C 6 alkylene)-, carboxyalkyl, cycloalkyl, cycloalkylalkyl, cyanoalkyl, haloalkyl, haloalkoxy-(C 2 -C 6 alkylene)-, heteroaryl, heteroarylalkyl, heteroaryloxy-(C 2 -C 6 alkylene)-, heteroarylcarbonyloxy-(C 2 -C 6 alkylene)-, heterocycle, heterocyclealkyl, heterocycleoxy-(C 2 -C 6 alkylene)-, hydroxy-(C 2 -C 6 alkylene)-, R a R b N—(C 2 -C 6 alkylene)-, RA J N—C(O)-alkylene-, R c R d N—C(O)—NR c —(C 2 -C 6 alkylene)-, R e O—N═C(R z )-alkylene-, or R f R g N—N═C(R z )-alkylene-;

R 2 and R 3 are each independently hydrogen, alkenyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkynyl, alkylcarbonyl, alkylsulfinyl, alkylsulfonyl, alkylthio, aryl, arylalkyl, arylalkenyl, azidoalkyl, cyano, cycloalkyl, formyl, halogen, haloalkyl, heteroaryl, heterocycle, hydroxyalkyl, hydroxyalkynyl, hydroxyhaloalkyl, R j R k N—, R j R k N-alkylene-, R m RN—C(O)—, R p O—N═C(R z )-alkylene-, R p O—N═C(R z )—, or R,R s N—N═C(R z )-alkylene-, or

R 2 and R 3 taken together with the carbon atoms to which they are attached form a heteroaryl, a heterocycle, or a cycloalkenyl ring;

R 4 is C 4 -C 10 alkyl, wherein the C 4 -C 10 alkyl group is optionally substituted with one substituent selected from the group consisting of hydroxy, alkoxy, haloalkoxy, cyano, —C(O)N(R z ) 2 , and —N(R z )C(O)R z ; alkenyl, alkynyl, naphthyl, arylalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, haloalkyl, heteroaryl, heteroarylalkyl, heterocycle, heterocyclealkyl, wherein the naphthyl, cycloalkyl, cycloalkenyl, heteroaryl, heterocycle, the aryl moiety of the arylalkyl, the cycloalkyl moiety of the cycloalkylalkyl, the cycloalkenyl moiety of the cycloalkenylalkyl, the heteroaryl moiety of the heteroarylalkyl, and the heterocycle moiety of the heterocyclealkyl are each independently unsubstituted or substituted with 1, 2, 3, 4, 5, or 6 substituents as represented by R 6 ;

or phenyl substituted with 1, 2, 3, 4, or 5 substituents as represented by R 6 ;

R 6 , at each occurrence, is independently selected from the group consisting of alkyl, alkenyl, alkynyl, nitro, cyano, halogen, haloalkyl, oxo, —OR eu , —O —(CR ju R ku ) x —N(R wu ) 2 , —OC(O )R eu , —SR eu , —S(O)R , —S(O) 2 R fu , —S(O) 2 N(R wu ) (R gu ), —N(R wu )(R gu ), —N(R wu )C(O )R eu , —N(R wu )C(O )0R eu , —N(R wu )S(O) 2 R fu , —N(R wu )C(O)N(R wu )(R gu ), —N(R wu )S(O) 2 N(R wii )(R gu ), —C (0)R eu —C(O )0(R eu ), —C(0)1I(R w AR gu ), haloalkyl, —(CR ju R ku ) x —CN, —(CR ju R ku ) x —OR eu , —(CR ju R ku ) x —OC(O )R eu , —(CR ju R ku ) x —SR eu , CR ju R ku ) x —S(O)R fu , —(CR ju R ku ) x —S(O) 2 R fu , —(CR ju R ku ) x —N(R wu )(R gu ), —(CR ju R ku ) x —N(R wu )C(0)R eu , —(CR ju R ku ) x —N(R wu )S(O) 2 R fu , —(CR ju R ku ) x —N(R wu )C(O)N(R wu )(R gu ), —(CR ju R ku ) x —N(R wu )S( 0 ) 2 N(R wu )(R gu ), —(CR ju R ku ) x —C(O)R eu , —(CR ju R ku ) x —C(O)0(R eu ), —(CR ju R ku ) x —C(0)N(R wu )(R gu ), —C(R wu )=N—OR wu , aryl, cycloalkyl, and heterocycle;

R wu , at each occurrence, is independently hydrogen, alkyl, or haloalkyl;

R eu and R gu , at each occurrence, are each independently hydrogen, alkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycle, haloalkoxyalkyl, or haloalkyl;

wherein the cycloalkyl, the heterocycle, and the cycloalkyl moiety of the cycloalkylalkyl are each independently unsubstituted or substituted with 1, 2, 3, 4, 5 or 6 substituents selected from the group consisting of alkyl, halogen, and haloalkyl;

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

R ju and R ku , at each occurrence, are each independently hydrogen, halogen, alkyl, or haloalkyl;

x is 1, 2, 3, 4, or 5;

R 5 is hydrogen, alkyl, alkenyl, alkynyl, cyano, or halogen;

L 2 is a bond, —N(R e )—or —O—;

R a and R b are each independently selected from the group consisting of hydrogen, alkyl, alkylcarbonyl, alkylsulfonyl, alkoxycarbonyl, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroarylalkyl, heterocycle, or heterocyclealkyl;

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

R e , at each occurrence, is independently hydrogen, alkyl, alkenyl, alkoxyalkyl, alkynyl, cyanoalkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, or hydroxyalkyl;

R f and R g , are each independently hydrogen, alkyl, alkenyl, alkoxycarbonyl, alkoxyalkyl, alkynyl, arylalkyl, cyanoalkyl, cycloalkylalkyl, haloalkyl, heteroarylalkyl, heterocyclealkyl, hydroxyalkyl or nitroalkyl; or R f and R g , together with the nitrogen atom to which they are attached, form a 5-, 6-, or 7-membered heterocycle ring;

j and R k , at each occurrence, are each independently hydrogen, alkyl, alkoxycarbonyl, alkylcarbonyl, alkylsulfonyl, arylalkyl, or —C(O)N(R z ) 2 ;

R m and R n are each independently hydrogen, alkyl, or haloalkyl;

R p , at each occurrence, is independently hydrogen, alkyl, alkenyl, alkoxyalkyl, alkynyl, cyanoalkyl, cycloalkylalkyl, haloalkyl, heterocyclealkyl, hydroxyalkyl, or nitroalkyl;

R r and R s are each independently hydrogen, alkyl, alkenyl, alkoxyalkyl, alkynyl, cyanoalkyl, cycloalkylalkyl, haloalkyl, heterocyclealkyl, hydroxyalkyl, or nitroalkyl; or R r and R s , together with the nitrogen atom to which they are attached, form a 5-, 6-, or 7- membered heterocycle ring; and

R z , at each occurrence, is independently hydrogen, alkyl, or haloalkyl;

with the proviso that when A is —C(R 2 ), R 2 is hydrogen or C 1 -C 5 alkyl, R 3 is hydrogen or phenyl, E is C(O), L 2 is a bond, and R 4 is aryl, then R 1 is not C 3 -C 5 alkyl, C 2 -C 5 alkenyl, C 2 -C 5 alkynyl, or (4-amino-2-methyl-5-pyrimindinyl)methyl.

2. The compound of claim 1 of formula (Ib) or a pharmaceutically acceptable salt thereof,

wherein R 1 , R 2 , R 3 , R 4 , R 5 , E, and L 2 are as defined in claim 1 .

3. The compound of claim 2 or a pharmaceutically acceptable salt thereof, wherein E is C(O) and L 2 is a bond.

4. The compound of claim 3 or a pharmaceutically acceptable salt thereof, wherein R 1 is C 3 -C 7 alkyl, alkylcarbonylalkyl, arylcarbonyloxy-(C 2 -C 6 alkylene)-, alkoxy-(C 2 -C 6 alkylene)-, cycloalkylalkyl, haloalkyl, or heterocyclealkyl.

5. The compound of claim 4 or a pharmaceutically acceptable salt thereof, wherein R 5 is hydrogen or halogen.

6. The compound of claim 5 or a pharmaceutically acceptable salt thereof, wherein R 4 is C 4 -C 10 alkyl, haloalkyl, naphthyl, arylalkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heterocycle, or substituted phenyl.

7. The compound of claim 2 or a pharmaceutically acceptable salt thereof, wherein

E is C(O);

L 2 is O;

R 1 is C 3 -C 7 alkyl;

R 5 is hydrogen; and

R 4 is cycloalkyl, C 4 -C io alkyl, or haloalkyl.

8. The compound of claim 2 or a pharmaceutically acceptable salt thereof, wherein

E is C(O);

L 2 is N(R e );

R e is hydrogen or alkyl;

R 1 is C 3 -C 7 alkyl;

R 5 is hydrogen; and

R 4 is substituted phenyl.

9. The compound of claim 2 or a pharmaceutically acceptable salt thereof wherein R 2 and R 3 taken together with the carbon atoms to which they are attached form, a heteroaryl, a heterocycle, or a cycloalkenyl ring.

10. The compound of claim 1 of formula (Id) or a pharmaceutically acceptable salt thereof

wherein

G is N(H), N(alkyl), 0, CH 2 , or CH 2 CH 2 ,

R 8 represents optional substituents selected from the group consisting of alkyl, halogen, and haloalkyl, two R 8 groups on the same carbon atom together with the carbon atom to which they are attached, optionally form a ═O group, and

E, R 1 , R 4 , R 5 , and L 2 are as set forth in claim 1 .

11. The compound of claim 10 or a pharmaceutically acceptable salt thereof wherein G is O, CH 2 , or CH 2 CH 2 .

12. The compound of claim 11 or a pharmaceutically acceptable salt thereof, wherein

E is C(O);

L 2 is a bond;

R 5 is hydrogen; and

R 1 is C 3 -C 7 alkyl.

13. A compound or a pharmaceutically acceptable salt thereof selected from the group consisting of (2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-1-(1-adamantyl)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanone;

tert-butyl (2Z)-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)acetate;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(2-methoxyethyl)-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-2-(3-butyl-5-methyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-cyclohexylethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-N-cyclohexylacetamide;

4-[(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]morpholine;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-N-(5-chloro-2-methoxyphenyl)acetamide;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-(3-propyl-1,3-benzothiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(5-bromo-3-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(5-acetyl-3-butyl-4-methylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(3-butyl-5-(1-(hydroxyimino)ethyl)-4-methylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-3-butyl-242-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-5-carbaldehyde;

(2Z)-3-butyl-242-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-5-carbaldehyde oxime;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[4,5-dimethyl-3-(2-morpholin-4-ylethyl)- 1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-3-butyl-2-(2-oxo-2-pyridin-2-ylethylidene)-2,3-dihydro-1,3-thiazole-5-carbaldehyde;

(2Z)-3-butyl-242-(3,5-difluorophenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-5-carbaldehyde;

(2Z)-3-butyl-242-(2-fluorophenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-5-carbaldehyde;

(2Z)-3-butyl-242-(2,4-difluorophenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-5-carbaldehyde;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2-fluorophenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-pyridin-2-ylethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(3,5-difluorophenyl)ethanone;

(2Z)-2-(3-butyl-3,4,5,6-tetrahydro-2H-cyclopenta[d][1,3]thiazol-2-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(5-acetyl-4-methyl-3-((tetrahydrofuran-2-yl)methyl)thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(5-acetyl-3-butyl-4-methylthiazole-2(3H)-ylidene-1-(pyridine-2-yl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(3-chlorothien-2-yl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(2-chloropyridin-3-yl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-cyclopentylethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-cyclohexylethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

6-[(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]-2,2-dimethyl-2,3-dihydro-4H-pyran-4-one;

(2Z)-1-(1-benzofuran-5-yl)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(5-fluoro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-4-phenyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

ethyl (2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazole-4-carboxylate;

(2Z)-2-(3-butyl-5-tert-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-N-(5-chloro-2-methoxyphenyl)acetamide;

(2Z)-2-(3-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-cyclohexylethanone;

(2Z)-2-(3-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-(3-chloro-l-benzothien-2-yl)ethanone;

(2Z)-1-(1-adamantyl)-2-(3-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2,6-difluorophenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2,4-dichlorophenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-[2- (trifluoromethyl)phenyl]ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-[3- (trifluoromethyl)phenyl]ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-cyclopentylethanone;

4-[(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]benzonitrile;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(1-naphthyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2,5-difluorophenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-pyridin-3-ylethanone;

(2Z)-1-(1,3-benzodioxo1-5-yl)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2-chloropyridin-3-yl)ethanone;

(2Z)-142,5-bis(trifluoromethyl)phenyl]-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-[5-fluoro-2-(trifluoromethyl)phenyl]ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(3-methylthien-2-yl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(5-fluoro-2-methylphenyl)ethanone;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-fluorophenyl)ethanone;

(Z)-2-(3-butyl-54(E)-1-(methoxyimino)ethyl)-4-methylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(3-butyl-54(Z)-1-(methoxyimino)ethyl)-4-methylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-[3-butyl-4-(trifluoromethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-[3-butyl-5-methyl-4-(trifluoromethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-1-(5-chloro-2-methoxyphenyl)-2-(54(E)-1-(methoxyimino)ethyl)-4-methyl-3-((tetrahydrofuran-2-yl)methyl)thiazol-2(3H)-ylidene)ethanone;

(Z)-1-(5-chloro-2-methoxyphenyl)-2-(54(Z)-1-(methoxyimino)ethyl)-4-methyl-3-((tetrahydrofuran-2-yl)methyl)thiazol-2(3H)-ylidene)ethanone;

(2Z)-3-butyl-242-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-5,5-dimethyl-2,3,5,6-tetrahydro-1,3-benzothiazol-7(4H)-one;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-(5-tert-butyl-3-isobutyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2[3-butyl-4-methyl-5-(2,2,2-trifluoro-1-hydroxy-1-methylethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-[5-tert-butyl-3-(tetrahydrofuran-2-ylmethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-]3-isobutyl-5-methyl-4-(trifluoromethyl)-1,3-thiazol-2(3H)-ylidene]ethanone;

(2E)-2-(3-butyl-4-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)-2-fluoroethanone;

(2E)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)-2-fluoroethanone;

(2Z)-2-(3-butyl-5-isopropenyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(1Z)- 1-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-4,4-dimethylpentan-2-one;

1-[(2Z)-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-4,5-dimethyl-1,3-thiazol-3(2H)-yl]-3,3-dimethylbutan-2-one;

1-adamantyl (2Z)-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)acetate;

(2Z)-2[3-butyl-5-(3-hydroxy-3-methylbut-1ynyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(1Z)-1-[3-(3,3-dimethyl-2-oxobutyl)-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene]-4,4-dimethylpentan-2-one;

(2E)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)-2-fluoroethanone;

2-[(2Z)-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-4,5-dimethyl-1,3-thiazol-3(2H)-yl[ethyl 5 -chloro-2-methoxybenzoate;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-[2-(methylamino)phenyl]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(4-fluorobutyl)-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-1-(2-amino-5-chlorophenyl)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanone;

ethyl 2-[(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]-4-chlorophenylcarbamate;

(2E)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(2-chloropyridin-3-yl)-2-fluoroethanone;

ethyl 2-[(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]-4-chlorophenyl(methyl)carbamate;

methyl 2-[(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]-4-chlorobenzoate;

(2Z)-2-[3-butyl-4-methyl-5-(2-methyl-1,3-dioxolan-2-yl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone; 2,2,2,-trichloro-1,1dimethylethyl (2Z)-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H) -ylidene)acetate;

(2Z)-2-[4-tert-butyl-3-(2-methoxyethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-[4-tert-butyl-3-(tetrahydrofuran-2-ylmethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2[4-tert-butyl-3-(2-piperidin-1-ylethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-N-methyl-2,3-dihydro-1,3-thiazole-4-carboxamide;

(Z)-2-(5-acetyl-3-butylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(2-chloropyridin-3-yl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(5-fluoro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(3-chlorothien-2-yl)ethanone;

6-[(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)ethanoyl]-2,2-dimethyl-2,3-dihydro-4H-pyran-4-one;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(5-iodo-2-methoxyphenyl)ethanone;

(2Z)-1-(1-benzofuran-5-yl)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-(2-ethoxypyridin-3-yl)ethanone;

(2Z)-1-(1-benzofuran-5-yl)-2-(3-butyl-5-isopropenyl-1,3-thiazol-2(3H)-ylidene)ethanone;

(2Z)-2-(3-butyl-5-isopropenyl-1,3-thiazol-2(3H)-ylidene)-1-(2-ethoxypyridin-3-yl)ethanone;

(2Z)-2-(3-butyl-4-methyl-1,3-thiazol-2(3H)-ylidene)-1-[trans-2-phenylcyclopropyl]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(1-hydroxy-1-methylethyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-2-[5-bromo-3-(cyclobutylmethyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-1,3-thiazol-2(3H)- ylidene]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-4-methyl-5-(2,2,2-trifluoro-1-hydroxy-1-methylethyl)-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-2[3-butyl-5-(1-hydroxy-1-methylethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(1-hydroxy-1-methylethyl)-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(1-ethyl-1-hydroxypropyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(2-fluoro-1-hydroxy-1-methylethyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(2,2-difluoro-1-hydroxy-1-methylethyl)-4-methyl-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-[2-(trifluoromethyl)phenyl]ethanone;

ethyl (2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-5-(1-hydroxy-l-methylethyl)-2,3-dihydro-1,3-thiazole-4-carboxylate;

(2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-6,6-dimethyl-3,6-dihydrofuro[3,4-d][1,3]thiazol-4(2H)-one;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-(5-chloro-2-hydroxyphenyl)ethanone;

tert-butyl (2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-2,3-dihydro-1,3-thiazol-4-ylcarbamate;

(2Z)-2-(3-butyl-4,5-dimethyl-1,3-thiazol-2(3H)-ylidene)-1-[5-chloro-2-(dimethylamino)phenyl]ethanone;

(2Z)- 1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-(1-ethyl-1-hydroxypropyl)-1,3-thiazol-2(3H)-ylidene]ethanone;

(2Z)-2-[5-(1-amino-1-ethylpropyl)-3-(cyclobutylmethyl)- 1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-5-tert-butyl-1,3-thiazol-2(3H)-ylidene)-1-[6-chloro-4-(trifluoromethyl)pyridin-3-yl]ethanone;

(2Z)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-6,6-diethyl-2,3,5,6-tetrahydro-4H-pyrrolo[3,4-d][1,3]thiazol-4-one;

(2Z)-2-[3-butyl-5-[2-fluoro-1-(fluoromethyl)-1-hydroxyethyl]-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-2-(3-butyl-5-isopropenyl-1,3-thiazol-2(3H)-ylidene)-1-[6-chloro-4-(trifluoromethyl)pyridin-3-yl]ethanone;

(2Z)-2[3-butyl-4-(1-hydroxy-1-methylethyl)-1,3-thiazol-2(3H)-ylidene]-1-(5-chloro-2-methoxyphenyl)ethanone;

(Z)-2-(4-acetyl-3-butylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanone;

(2Z)-1-(5-chloro-2-methoxyphenyl)-2-[3-(cyclobutylmethyl)-5-[2-fluoro-1-(fluoromethyl)-1-hydroxyethyl]-4-methyl-1,3-thiazol-2(3H)-ylidene]ethanone;

ethyl (2Z)-5-(1 -amino-1-methylethyl)-3-butyl-2-[2-(5-chloro-2-methoxyphenyl)- 2-oxoethylidene]-2,3-dihydro-1,3-thiazole-4-carboxylate;

(2Z)-3-butyl-2[2-(5-chloro-2-methoxyphenyl)-2-oxoethylidene]-6,6-dimethyl-2,3,5,6-tetrahydro-4H-pyrrolo[3,4-d][1,3]thiazol-4-one; and

(Z)-2-(3-butyl-4,5-dimethylthiazol-2(3H)-ylidene)-1-(5-chloro-2-methoxyphenyl)ethanethione.

14. A pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 of formula (I), or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable carrier.

15. A method for treating pain in a mammal in need of such treatment comprising administering to the mammal a therapeutically effective amount of a compound of claim 1 of formula (I), or a pharmaceutically acceptable salt thereof.