| abstract |
The present invention provides compounds of the general formula: <CHEM> wherein R<1> is a hydroxyl or protected hydroxyl group or a carboxyl group or a lower alkoxycarbonyl or benzyloxy radical, R<2> is a hydrogen or halogen atom or a halo(lower)alkyl radical, R<3> is a hydrogen atom, a hydroxyl group or a lower alkoxy radical and A is a lower alkylene radical; and the pharmaceutically acceptable salts thereof. The present invention also provides processes for the preparation of these compounds and pharmaceutical compositions containing them and is also concerned with the use thereof. |