Patent ID: 7521469

Claim:
A compound selected from those of formula (I): wherein: R 1 represents a hydrogen atom, a (C 1 -C 6 )alkyl-carbonyloxy-(C 1 -C 6 )alkyl group in which the alkyl moiety may be linear or branched, or a (C 1 -C 6 )alkyl-carbonylthio-(C 1 -C 6 )alkyl group in which the alkyl moiety may be linear or branched, R 2 represents a hydrogen atom, a (C 1 -C 6 )alkyl-carbonyloxy-(C 1 -C 6 )alkyl group in which the alkyl moiety may be linear or branched, an arylcarbonylthio-(C 1 -C 6 )alkyl group in which the alkyl moiety may be linear or branched, or an aryl-(C 1 -C 6 )alkyl group in which the alkyl moiety may be linear or branched and the aryl moiety may be optionally substituted by a (C 1 -C 6 )alkyl-carbonyloxy group, R 3 represents a phenyl group, optionally substituted by a hydroxy group, or 3-indolyl group, or R 1 may also represent a linear or branched (C 1 -C 6 )alkyl group and R 2 represents a linear or branched (C 1 -C 6 )alkyl group, when R 3 represents a phenyl group substituted by a hydroxy group, its enantiomers and diastereoisomers, and addition salts thereof with a pharmaceutically acceptable base.