Thiazole derivatives

An organic compound of the general formula where R1 and R2 are cyano, formyl, substituted or unsubstituted alkanoyl or aroyl, a carboxylic acid ester group, substituted or unsubstituted carbamoyl or sulfamoyl, alkylsulfonyl, arylsulfonyl or alkylsulfinyl, or R1 and R2 together may be a cyclic radical, R2 may also be alkyl, aryl or hetaryl, R3 is hydrogen, substituted or unsubstituted alkyl, aryl or hetaryl, X is CH, CR5 or N, R4 is a radical of the formula +TR R5 to R10 are substituents conventionally present in dyes. The compounds may be used as dyes for synthetic and natural fibers and give very fast dyeings.