Abstract: Compounds of general formula (I): wherein R1, R2, R3 and R4 are independently hydrogen, halo, C1-C6 alkyl, —O(C1-C6 alkyl), —CON(R9)2, —SOR9, —SO2R9, —SO2N(R9)2, —N(R9)2, —NR9COR9, —CO2R9, —COR9, —SR9, —OH, —NO2 or —CN; each R9 is independently hydrogen or C1-C6 alkyl; R5 and R6 are each independently hydrogen, or C1-C6 alkyl or together with the carbon atom to which they are attached form a C3-C7 cycloalkyl group; R7 is hydrogen or C1-C6 alkyl n is 1 or 2; X is a bond or, when n is 2, X may also be a NR9 group; wherein R9 is as defined above; when X is a bond R8 is C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, biphenyl or a 9-14 membered bicyclic or tricyclic heteroaryl group; when X is a NR9 group R8 may additionally be phenyl, naphthyl or a 5-7 membered heteroaromatic ring; and the R8 group is optionally substituted with one or more substituents selected from halo, C1-C6 alkyl, —O(C1-C6)alkyl, aryl, —O-aryl, heteroaryl, —O-heteroaryl, —CON(R9)2, —SOR9, —SO2R9, SO2N(9)2, —N(9)2, —NR9COR9, —CO2