Patent ID: 6960664

Claim:
A compound of the formula V: or a pharmaceutically acceptable salt thereof wherein R 1 represents phenyl (C 1 -C 6 )alkyl where the phenyl is optionally substituted with up to three groups independently selected from halogen, hydroxy, C 1 -C 2 alkyl, C 1 -C 2 alkoxy, amino, nitro, trifluoromethyl, cyano, mono(C 1 -C 2 )alkylamino and di (C 1 -C 2 ) alkylamino; R a and R b independently represent hydrogen, hydroxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkoxy, halogen, cyano, amino, mono(C 1 -C 6 )alkylamino, di(C 1 -C 6 )alkylamino, mono- or di(C 1 -C6)alkylaminosulfonyl, C 1 -C 6 alkyl sulfonylamino, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, trifluoromethyl, mono(C 1 -C 6 )alkylaminocarbonyl, or di(C 1 -C 6 ) alkylaminocarbonyl and provided that not both R a and R b are hydrogen simultaneously; R c represents hydrogen, or C 1 -C 6 alkyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl each of which is optionally substituted with halogen, hydroxy, amino, cyano, or trifluoromethyl; R d represents phenyl optionally substituted with hydroxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloalkyl (C 1 -C 6 )alkyl, C 3 -C 7 cycloalkyl(C 1 -C 6 )alkoxy, halogen, cyano, amino, mono(C 1 -C 6 )alkylamino, di(C 1 -C 6 )alkylamino, mono- or di(C 1 -C 6 )alkylaminosulfonyl, C 1 -C 6 alkyl sulfonylamino, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl; or C 1 -C 6 alkyl optionally substituted with hydroxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, halogen, cyano, amino, mono(C 1 -C 6 )alkylamino, di(C 1 -C 6 )alkylamino, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or trifluoromethyl; and R 20 represents hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or trifluoromethyl.