A compound of formula, or a pharmaceutically acceptable salt, solvate or N- oxide thereof: wherein Y represents a linkage of formula C or S 2; R 1 represents hydrogen, halogen, cyano, nitro, C 1-6 alkyl, trifluoromethyl, C 1-6 alkoxy, trifluoromethoxy, C 1-6 alkylthio, C 1-6 alkylsulphinyl or C 1-6 alkylsulphonyl; R 2 represents halogen, nitro, cyano, C 1-6 alkyl, C 2-6 alkynyl, hydroxy(C 1-6)alkyl or formyl; and R 3 represents a group of formula (a), (b), (c), (d) or (e): wherein the asterisk (*) represents the point of attachment to the remainder of the molecule; R 4 and R 5 independently represent hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylamino(C 1-6)alkoxy, C 1-6 alkoxy(C 1-6)alkyl, C 1-6 alkylthio, C 1-6 alkylsulphonyl, hydroxy, hydroxy(C 1-6)alkyl, amino(C 1-6)alkyl, nitro(C 1-6)alkyl, cyano, trifluoromethyl, C 2-6 alkylcarbonyl, carboxy, C 2-6 alkoxycarbonyl, azido, amino, C 1-6 alkylamino, di(C 1-6)alkylamino, bis[hydroxy(C 1-6)alkyl]amino, C 1-6 alkylamino(C 1-6)alkylamino, arylamino, heteroarylamino, C 2-6 alkylcarbonylamino, C 2-6 alkoxycarbonylamino, [(C 2-6)alkoxycarbonyl] [(C 1-6)alkyl]amino, bis[(C 2-6)alkoxycarbonyl(C 1-6)alkyl]amino, C 2-6 alkoxycarbonylamino(C 1-6)alkyl or aminocarbonyl; X represents a covalent bond, or a linkage of formula C, S 2, C O or C N(R 7); R 6 represents hydrogen or trifluoromethyl; or C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl(C 1-6)alkyl, aryl, aryl(C 1-6)alkyl, C 3-7 heterocycloalkyl, C 3-7 heterocycloalkyl-(C 1-6)alkyl, heteroaryl or heteroaryl(C 1-6)alkyl, any of which groups may be optionally substituted by one or more substituents; and R 7 represents hydrogen or C 1-6 alkyl. Y represents a linkage of formula C or S 2; R 1 represents hydrogen, halogen, cyano, nitro, C 1-6 alkyl, trifluoromethyl, C 1-6 alkoxy, trifluoromethoxy, C 1-6 alkylthio, C 1-6 alkylsulphinyl or C 1-6 alkylsulphonyl; R 2 represents halogen, nitro, cyano, C 1-6 alkyl, C 2-6 alkynyl, hydroxy(C 1-6)alkyl or formyl; and R 3 represents a group of formula (a), (b), (c), (d) or (e): wherein the asterisk (*) represents the point of attachment to the remainder of the molecule; R 4 and R 5 independently represent hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylamino(C 1-6)alkoxy, C 1-6 alkoxy(C 1-6)alkyl, C 1-6 alkylthio, C 1-6 alkylsulphonyl, hydroxy, hydroxy(C 1-6)alkyl, amino(C 1-6)alkyl, nitro(C 1-6)alkyl, cyano, trifluoromethyl, C 2-6 alkylcarbonyl, carboxy, C 2-6 alkoxycarbonyl, azido, amino, C 1-6 alkylamino, di(C 1-6)alkylamino, bis[hydroxy(C 1-6)alkyl]amino, C 1-6 alkylamino(C 1-6)alkylamino, arylamino, heteroarylamino, C 2-6 alkylcarbonylamino, C 2-6 alkoxycarbonylamino, [(C 2-6)alkoxycarbonyl] [(C 1-6)alkyl]amino, bis[(C 2-6)alkoxycarbonyl(C 1-6)alkyl]amino, C 2-6 alkoxycarbonylamino(C 1-6)alkyl or aminocarbonyl; X represents a covalent bond, or a linkage of formula C, S 2, C O or C N(R 7); R 6 represents hydrogen or trifluoromethyl; or C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl(C 1-6)alkyl, aryl, aryl(C 1-6)alkyl, C 3-7 heterocycloalkyl, C 3-7 heterocycloalkyl-(C 1-6)alkyl, heteroaryl or heteroaryl(C 1-6)alkyl, any of which groups may be optionally substituted by one or more substituents; and R 7 represents hydrogen or C 1-6 alkyl. wherein the asterisk (*) represents the point of attachment to the remainder of the molecule; R 4 and R 5 independently represent hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylamino(C 1-6)alkoxy, C 1-6 alkoxy(C 1-6)alkyl, C 1-6 alkylthio, C 1-6 alkylsulphonyl, hydroxy, hydroxy(C 1-6)alkyl, amino(C 1-6)alkyl, nitro(C 1-6)alkyl, cyano, trifluoromethyl, C 2-6 alkylcarbonyl, carboxy, C 2-6 alkoxycarbonyl, azido, amino, C 1-6 alkylamino, di(C 1-6)alkylamino, bis[hydroxy(C 1-6)alkyl]amino, C 1-6 alkylamino(C 1-6)alkylamino, arylamino, heteroarylamino, C 2-6 alkylcarbonylamino, C 2-6 alkoxycarbonylamino, [(C 2-6)alkoxycarbonyl] [(C 1-6)alkyl]amino, bis[(C 2-6)alkoxycarbonyl(C 1-6)alkyl]amino, C 2-6 alkoxycarbonylamino(C 1-6)alkyl or aminocarbonyl; X represents a covalent bond, or a linkage of formula C, S 2, C O or C N(R 7); R 6 represents hydrogen or trifluoromethyl; or C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl(C 1-6)alkyl, aryl, aryl(C 1-6)alkyl, C 3-7 heterocycloalkyl, C 3-7 heterocycloalkyl-(C 1-6)alkyl, heteroaryl or heteroaryl(C 1-6)alkyl, any of which groups may be optionally substituted by one or more substituents; and R 7 represents hydrogen or C 1-6 alkyl.