(4,2-Disubstituted-thiazol-5-yl)amine compounds as PDE7 inhibitors

A compound of formula (I):

• 14
• wherein:
• R1a is a group selected from hydrogen, (C1-C6)alkyl and aryl(C1-C6)alkyl,
• R1b is a group selected from cycloalkyl, heterocycloalkyl, aryl and heteroaryl, those groups being optionally substituted by one or more groups, identical or different, selected independently of each other from halogen, trifluoromethyl, nitro, cyano, oxo, —NR4R5, —CO2R4, —CONR4R5, —OR4, —S(O)nR4, —S(O)nNR4R5, tetrazolyl, and (C1-C6)alkyl which is optionally substituted by 1 to 3 groups, identical or different, selected independently of each other from —OR4, —NR4R5, and —CO2R4, wherein:
• n is an integer from 0 to 2 inclusive,
• R4 and R5 are identical or different and independently of each other are a hydrogen atom or a group of formula —X1—Ra wherein:
• X1 is a single bond or a (C1-C6)alkylene group,
• Ra is a group selected from (C1-C6)alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl,
• R2 is a group selected from (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, aryl and cycloalkyl,
• R3 is a group selected from cycloalkyl, heterocycloalkyl, aryl and heteroaryl, these groups being optionally substituted by one or more groups, identical or different, selected independently of each other from halogen, nitro, cyano, trifluoromethyl, oxo, (C1-C6)alkyl, —OR6, —NR6R7, —COR6, —CO2R6, —CONHOH, —CONR6R7, —S(O)mR6, —S(O)m—NR6R7, —NR6COR7, —NR6SO2R7, —N(SO2R7)2, —NR6—CO—NR7R8, C(═N—CN)NR6R7, NR8—C(═N—CN)NR6R7 and tetrazolyl optionally substituted with a (C1-C4)alkyl, wherein:
• m is an integer from 0 to 2 inclusive,
• R6 and R7 are identical or different and independently of each other are a hydrogen atom or a group of formula —X2—Rb wherein:
• X2 is a single bond or a (C1-C6)alkylene group,
• Rb is a group selected from (C1-C6)alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl, these groups being optionally substituted by 1 to 3 groups, identical or different, selected independently of each other from hydroxy, (C1-C6)alkoxy, (C1-C6)alkyl, amino, mono(C1-C6)alkylamino, di(C1-C6)alkylamino (each alkyl amino being identical or different, independently of each other), carboxy, (C1-C6)alkoxycarbonyl, and benzyl,
• R8 is a hydrogen atom or a (C1-C6)alkyl group,
• a racemic form thereof, an isomer thereof, an N-oxide thereof or a pharmaceutically acceptable acid or base salt thereof, provided that
• (4-methyl-2-phenyl-thiazol-5-yl)-phenyl-amine,
• (2,4-diphenyl-thiazol-5-yl)-phenyl-amine,
• (2,4-diphenyl-thiazol-5-yl)-(3-fluoro-phenyl)-amine,
• (2,4-diphenyl-thiazol-5-yl)-(4-fluoro-phenyl)-amine,
• (4-chloro-phenyl)-(2,4-diphenyl-thiazol-5-yl)-amine,
• (2-chloro-phenyl)-(2,4-diphenyl-thiazol-5-yl)-amine,
• (2,4-diphenyl-thiazol-5-yl)-p-tolyl-amine and
• (2,4-diphenyl-thiazol-5-yl)-(4-methoxy-phenyl)-amine are excluded.