Preferably when Z represents NR3R4 R3 represents H and R4 represents Y???(C???O)???T???R5 the said NH and said (C???O) are positioned ortho to each other on Y (which is phenyl), T is a bond or ???O???, R5 is C1-6 alkyl, or phenyl (optionally substituted by one or more: halogen atoms, C1-3 alkyl, C1-3 alkoxy groups, C0-3alkyleneNR9R10 where each R9 and R10 is independently hydrogen, C1-3 alkyl, ???