Abstract: Compounds of formula (I), wherein: R1 represents a substituent selected from: a hydrogen or halogen atom; a hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, trifluoromethanesulfonyloxy, pentafluoroethyl, C1-4alkyl, C1-4alkoxy, arylC1-4alkoxy, C1-4alkylthio, C1-4alkoxyC1-4alkyl, C3-6cycloalkylC1-4alkoxy, C1-4alkanoyl, C1-4alkoxycarbonyl, C1-4alkylsulfonyl, C1-4alkylsulfonyloxy, C1-4alkylsulfonylC1-4alkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonylC1-4alkyl, C1-4alkylsulfonamido, C1-4alkylamido, C1-4alkylsulfonamidoC1-4alkyl, C1-4alkylamidoC1-4alkyl, arylsulfonamido, arylcarboxamido, arylsulfonamidoC1-4alkyl, arylcarboxamidoC1-4alkyl, aroyl, aroylC1-4alkyl, or arylC1-4alkanoyl group; a group R3OCO(CH2)p, R3CON(R4)(CH2)p, R3R4NCO(CH2)p or R3R4NSO2(CH2)p where each of R3 and R4 independently represents a hydrogen atom or a C1-4alkyl group or R3R4 forms part of a C3-6azacyloalkane or C3-6(2-oxo)azacycloalkane ring and p represents zero or an integer from 1 to 4; or a group Ar1—Z,