Patent ID: 8236790

Claim:
A compound of formula (I): wherein: R 1 and R 2 , which may be the same or different, each represent a hydrogen atom; a halogen atom; a linear or branched (C 1 -C 6 )alkyl group which is unsubstituted or substituted by one or more halogen atoms; a linear or branched (C 1 -C 6 )alkoxy group; a linear or branched (C 1 -C 6 )alkylthio group; a linear or branched (C 1 -C 6 )alkoxycarbonyl group; a carboxy group; a linear or branched (C 1 -C 6 )acyl group; a hydroxy group; a linear or branched (C 1 -C 6 )hydroxyalkyl group; a cyano group; a nitro group; an amino group which is unsubstituted or substituted by one or more linear or branched (C 1 -C 6 )alkyl groups; an amino group which is substituted by a linear or branched (C 1 -C 6 )acyl group; an aminocarbonyl group which is unsubstituted or substituted by one or more linear or branched (C 1 -C 6 )alkyl groups; an aminosulphonyl group which is unsubstituted or substituted by one or more linear or branched (C 1 -C 6 )alkyl groups; a (C 1 -C 6 )alkyl-sulphonylamino-(C 1 -C 6 )alkyl group in which the alkyl moieties are linear or branched; an N-hydroxycarboximidamide group; or a benzyloxy group, R 3 represents a hydrogen atom; a linear or branched (C 1 -C 6 )alkyl group; a (C 3 -C 8 )cycloalkyl group or a (C 3 -C 8 )cycloalkyl-(C 1 -C 6 )alkyl group in which the alkyl moiety is linear or branched, R 4 represents a hydrogen atom or a linear or branched (C 1 -C 6 )alkyl group which is unsubstituted or substituted by one or more halogen atoms, or an optical isomer or addition salt thereof with a pharmaceutically acceptable acid or base.