A compound of formula, or a pharmaceutically acceptable salt, solvate or N- oxide thereof: wherein Q represents the residue of a three-, four-, five- or six-membered heterocyclic ring optionally containing one or two double bonds, wherein the heterocyclic ring comprises one, two or three heteroatoms independently selected from oxygen, sulphur, nitrogen and phosphorus; 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; R 3 and R 4, where present, 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, halogen, cyano, trifluoromethyl, aryl, aryl(C 1-6)alkyl, C 3-7 heterocycloalkyl(C 1-6)alkyl, heteroaryl, heteroaryl(C 1-6)alkyl, oxo, thioxo, imino, C 2-6 alkylcarbonyl, carboxy, C 2-6 alkoxycarbonyl, 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, C 3-7 cycloalkylamino, arylamino, heteroarylamino, C 2-6 alkylcarbonylamino, C 2-6 alkoxycarbonylamino, (C 2-6)alkoxycarbonyl(C 1-6)alkylamino, [(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; or R 3 and R 4, when both are attached to the same carbon atom, represent, when taken together with the carbon atom to which they are both attached, C 3-7 cycloalkyl or C 3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents independently selected from C 1-6 alkyl, hydroxy and amino; and R 5, where present, represents hydrogen or C 1-6 alkyl. Q represents the residue of a three-, four-, five- or six-membered heterocyclic ring optionally containing one or two double bonds, wherein the heterocyclic ring comprises one, two or three heteroatoms independently selected from oxygen, sulphur, nitrogen and phosphorus; 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; R 3 and R 4, where present, 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, halogen, cyano, trifluoromethyl, aryl, aryl(C 1-6)alkyl, C 3-7 heterocycloalkyl(C 1-6)alkyl, heteroaryl, heteroaryl(C 1-6)alkyl, oxo, thioxo, imino, C 2-6 alkylcarbonyl, carboxy, C 2-6 alkoxycarbonyl, 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, C 3-7 cycloalkylamino, arylamino, heteroarylamino, C 2-6 alkylcarbonylamino, C 2-6 alkoxycarbonylamino, (C 2-6)alkoxycarbonyl(C 1-6)alkylamino, [(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; or R 3 and R 4, when both are attached to the same carbon atom, represent, when taken together with the carbon atom to which they are both attached, C 3-7 cycloalkyl or C 3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents independently selected from C 1-6 alkyl, hydroxy and amino; and R 5, where present, represents hydrogen or C 1-6 alkyl.