Synthesis, Characterization, and Dyeing Performance of Thiadiazole Derivatives

N4-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine derivatives have been synthesized by the reaction of 2-amino-5-methyl-1,3,4-thiadiazole and chloroaecetylchloride with suitable solvent, then cyclized with thiourea at reflux temperature in methanol to yield N4-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine which was diazotized and coupled with various naphthalene acid couplers to give new series of acid dyes (AD1-AD13). All the compounds were characterized by their percentage yield, melting point, elemental analysis, UV spectra, IR spectra, and NMR spectra and dyeing performance on nylon fabric has been assessed.