Patent ID: 7642269

Claim:
A compound of the formula (I) or a pharmaceutically acceptable salt thereof: wherein: R 1 is hydrogen; a straight or branched C 1 -C 6 alkyl group, optionally substituted with one or more substituents selected from the group consisting of C 1 -C 5 alkoxy, hydroxy, C 3 -C 7 cycloalkyl, acetoxy, C 2 -C 6 alkenyloxy, C 1 -C 3 alkoxycarbonyl, amino optionally one or two substituted with C 1 -C 3 alkyl, cyano, naphthyl, pyridyl, oxiranyl, oxazolidinonyl, isoxazolyl optionally one or more substituted with C 1 -C 3 alkyl, 1,3-dioxolanyl, and 2,3-dihydrobenzo[1,4]dioxinyl; a straight or branched C 2 -C 6 alkenyl group; a straight or branched C 2 -C 6 alkynyl group; or a benzyl group, optionally substituted with one or more substituents selected from the group consisting of halogen, C 1 -C 3 alkyl, C 1 -C 3 alkoxy, cyano, C 1 -C 3 alkoxycarbonyl, and trifluoro-C 1 -C 3 alkyl, R 2 is a straight or branched C 1 -C 6 alkyl group, R 3 is a straight or branched C 1 -C 6 alkyl group optionally substituted with hydroxy, R 4 is hydrogen; a straight or branched C 1 -C 6 alkyl group; halogen; cyano; hydroxycarbonyl; aminocarbonyl; or C 3 -C 7 cycloalkyl-aminocarbonyl, R 5 is a 1,2,3,4-tetrahydroisoquinolinyl group optionally one or more substituted with halogen or C 1 -C 5 alkyl; a benzyloxy group optionally substituted with one or more substituents selected from the group consisting of halogen, C 1 -C 5 alkyl, C 1 -C 5 alkoxy, and trifluoro-C 1 -C 3 alkyl; an amino group optionally substituted with one or two substituents selected from the group consisting of C 1 -C 5 alkoxy-carbonyl and benzyl optionally substituted with halogen; a phenyl group optionally one or more substituted with halogen; a phenoxy group optionally one or more substituted with halogen; a pyridyl-C 1 -C 3 alkoxy group; or a piperonyloxy group, and n is 1 or 2.