Chemical compounds

A compound of formula (I) (see formula) wherein: R 1 and R 2 are independently selected from hydrogen, halo, nitro, cyano, hydroxy, trifluoromethoxy, amino, carboxy, carbamoyl, mercapto, sulfamoyl, C1 - 6 C2 - 6 alkynyl C2 - 6 alkoxy C1 - 6 alkanoyl C1 - 6 alkanoyloxy C1 - 6, N- (C1 - 6) amino, N, N- (C1 - 6) 2amino, alkanoylamino C1 - 6, N- (C1 - 6) carbamoyl, N, N- (C1 - 6) 2carbamoílo, [C1 - 6] S (O) a wherein a is 0 to 2, alkoxycarbonyl C1 - 6, N- (C1 - 6) sulphamoyl, N, N- (C1 - 6) 2sulfamoílo, [C1 - 6] alkylsulfonylamino, carbocyclyl or heterocyclyl; wherein R 1 and R 2 independently of one another, may be optionally substituted on carbon by one or more R 8 and wherein if said heterocyclyl contains an -NH- moiety that nitrogen may be optionally substituted by a group selected from R 9; X 1, X 2 and X 3 are independently = N- or = CR 10 -; R 3 and R 10 are independently selected from hydrogen, halo, nitro, cyano, hydroxy, trifluoromethoxy, amino, carboxy, carbamoyl, mercapto, sulfamoyl, C1 - 6 C2 - 6 alkynyl C2 - 6 alkoxy C1 - 6 alkanoyl C1 - 6 alkanoyloxy C1 - 6, N- (C1 - 6) amino, N, N- (C1 - 6) 2amino, alkanoylamino C1 - 6, N- (C1 - 6) carbamoyl, N , N- (C1 - 6) 2carbamoílo, [C1 - 6] s (O) a wherein a is 0 to 2, alkoxycarbonyl C1 - 6, N- (C1 - 6) sulphamoyl, N, N- (C1 - 6) 2sulfamoílo [C1 - 6] sulfonylamino, carbocyclyl-R 11 - or heterocyclyl-R 12 -; wherein R 3 and R 10 independently of one another, may be optionally substituted on carbon by one or more R 13 and wherein if said heterocyclyl contains an -NH- moiety that nitrogen may be optionally substituted by a group selected from R 14; R 4 is ...