The invention provides compounds of general formula (I) wherein R1 is H or C1-C6 alkyl; R2 and R3, together with the interconnecting atoms form a 4 to 8-membered saturated ring containing one or two heteroatoms (including the nitrogen to which R2 is attached) wherein a second heteroatom, if present, is selected from oxygen, nitrogen and sulfur, with the proviso that said ring cannot contain two adjacent heteroatoms; Z is CF3, OCF3, C1-C6alkylthio or C1-C6alkoxy; Y is hydrogen, halogen, —ORa, Ra or C1-C6alkylthio, and wherein Ra is C1-C4 alkyl optionally substituted with fluorine atoms; or when Z and Y are attached para and meta to the ether linkage linking rings A and B, Z and Y are linked so that, together with the interconnecting atoms, Z and Y form a fused 5 to 7-membered carbocyclic or heterocyclic ring which may be saturated, unsaturated or aromatic, and wherein when Z and Y form a heterocyclic ring, in addition to carbon atoms, the linkage contains one or two heteroatoms independently selected from oxygen, sulfur and nitrogen; and Z and Y together do not form a fused phenyl ring; R4 and R5, which may be the same or different, are: A—X, wherein A=—CH═CH— or —(CH2)p— where p is 0, 1 or 2; X is hydrogen, F, Cl, Br, I, CONR6R7, SO2NR6R7, SO2NHC(═O)R6, OH, C1-4alkoxy, NR8SO2R9, NO2, NR6R11, CN, CO2R10, CHO, SR10, S(O)R9 or SO2R10; or a 5- or 6-membered heterocyclic ring containing 1, 2 or 3 heteroatoms selected from N, S and O, optionally substituted independently by one or more R13; wherein R13 is hydroxy, C1-C4alkoxy, F, C1-C6alkyl, haloalkyl, haloalkoxy, —NH2, —NH(C1-C6alkyl) or —N(C1-C6alkyl)2.