A compound of formula (I): ** Formula ** or a pharmaceutically acceptable salt, solvate or polymorph thereof, including all tautomers and stereoisomers thereof, wherein: R1 represents hydrogen, halogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, -aryl, -C 1-6 alkyl-aryl, -cycloalkyl, -C 1-6 alkyl-cycloalkyl, -heteroaryl, -C 1-6 alkyl-heteroaryl, -heterocyclyl, -C 1-6 alkyl 6-heterocyclyl, -phenyl substituted cycloalkyl, -phenoxy substituted cycloalkyl, -cycloalkyl substituted phenyl, -phenyl substituted phenyl, phenyl substituted phenyl, phenyl substituted heterocyclyl, phenyl substituted heteroaryl, heterocyclyl substituted phenyl substituted with heteroaryl, phenyl substituted with -O-cycloalkyl, phenyl substituted with -heterocyclylphenyl or phenyl substituted with -cycloalkyl-heterocyclyl； and wherein any of the aforementioned aryl, cycloalkyl, heterocyclyl, heteroaryl, phenyl or phenoxy groups may be optionally substituted with one or more Rb groups selected from C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl , -C 1-6 thioalkyl, -SO-C 1-4 alkyl, -SO 2 -C 1-4 alkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, -C 3-8 cycloalkyl, C 3-8 cycloalkyl, -SO 2 -cycloalkyl 3-8, -SO-C3-6 cycloalkyl, C3-6 alkenyloxy, C3-6 alkynyloxy, -C (O) -C1-6 alkyl, -C (O) O-C1-6 alkyl, C1- alkoxy 6-C1-6- alkyl, nitro, halogen, cyano, hydroxyl,>； = O, -C (O) OH, -NH2, -NH-C1-4 alkyl, -N (C1-4 alkyl) (C1- alkyl 4), -C (O) N (C1-4 alkyl) (C1-4 alkyl), -C (O) NH2, -C (O) NH (C1-4 alkyl) and -C (O) NH (cycloalkyl C3-10)； R2 represents -O-C1-6 alkyl, -NR3R4 or -O-C1-6 haloalkyl； R3 and R4 independently represent hydrogen, C1-6 alkyl or C3-8 cycloalkyl； or R3 and R4 together with the nitrogen atom to which they are attached can form a heterocyclyl group optionally substituted with one or more Rb groups； n represents an integer selected from 0 to 3； and Ra represents C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 1-6 haloalkyl, C 1-6 thioalkyl, -SO-C 1-4 alkyl, -SO 2 -C 1-4 alkyl, C 1-6 alkoxy , -O-C
