Patent ID: 8309341

Claim:
A compound of formula (I): wherein: R 1 represents a hydrogen atom; a group of formula COR 4 wherein R 4 represents a linear or branched C 1 -C 6 alkyl group or an aryl group; or a group of formula (A): R 2 represents a group of formula NR 5 R 6 wherein R 5 and R 6 , which may be the same or different, each represent a hydrogen atom or a linear or branched C 1 -C 6 alkyl group, a nitrogen-containing heterocyclic group, an aryl group, or a heteroaryl group; R3 represents a hydrogen atom or a linear or branched C 1 -C 6 alkyl group; m represents an integer between 1 and 6 inclusive; and n represents 0, 1, or 2, or an optical isomer thereof, or a pharmaceutically acceptable acid addition salt thereof.