| abstract |
The present invention provides compounds of formula (I) wherein A represents OH, NH2, COOR3', OCONHR4, CONHR4, NHCOR4, NHCO2R4, NHC(X)NHR4, NHC(X)NHCOR4, (a) or (b), R1 is hydrogen or C1-4 linear or branched alkyl; R2 is hydrogen, chlorine, bromine or an S-C1-4 alkyl group; R3 and R3' are, independently. C1-5 alkyl or hydrogen, n is 0,1 or 2, m is 1 or 2; R4 is hydrogen, C1-7 alkyl, C3-7 cycloalkyl, adamantidyl (tricycle 3.3.1.1 3,7) decan-1-yl, C1-5 alkylphenyl, C2 alkenylphenyl; C2 alkynylphenyl, phenyl optionally substituted by one or more groups selected from C1-4 alkyl, C1-3 alkoxy, methylendioxy, cyano, trifluoromethyl, hydroxy, nitro and acetyl; an optionally substituted naphthyl ring or phenyl condensed with a heterocyclic ring system having 5- or 6- ring members including 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, a heterocyclic ring having 5 or 6 ring members including 1 or 2 heteroatoms selected from nitrogen, oxygen and sulphur which is optionally substituted by a group selected from C1-4 alkyl, phenyl optionally substituted as defined above, C1-3 alkoxy and halogen; R3 is hydrogen, C1-4 alkyl or a phenyl group and X is NH, O, S; or a pharmaceutically acceptable salt thereof. A process for their preparation and the pharmaceutical compositions comprising them are also provided. |