Oxysalicylamido derivatives

Novel therapeutically active compounds of the formula I wherein Zi, being Z1, Z2 or Z3, is the same or different and selected among OH, OR1, NH2, NR24, NHR4, SH, SR4 and OR4 wherein R1 is a formyl group, an acyl group, an alkoxycarbonyl group or a mono- or dialkylcarbamoyl group and R4 is a lower alkyl group, R2 is a hydrogen, a halogen, a lower alkyl or a lower trifluoroalkyl group, R3 is a hydrogen atom, a lower alkyl group, an alkenyl group, an alkynyl group or a phenyl group, which phenyl group could optionally be substituted by one or more of fluoro, chloro, bromo, trifluoromethyl, methyl, ethyl, methoxy or ethoxy in the ortho, meta or para positions, or optionally substituted by methylenedioxy, provided that at least one of Z1, Z2 and Z3 is a group OR4 and further provided that when Z2 is OH or NH2, Z1 is NR24, NHR4, SH, SR4 or OR4 or a physiologically acceptable salt or optical isomer thereof, intermediates and methods for their preparation, pharmaceutical preparations containing the compounds and methods for their therapeutical use.