SYNTHESIS AND EVALUATION OF COUPLER 4-ARYL-2-AMINOTHIOPHENE-3-CARBONITRILE AND ITS DERIVATIVES AS POTENTIAL COUPLING COMPONENT IN DYE SYNTHESIS

Thiophene nucleus has been established as the potential entity in the large growing chemical world of heterocyclic compounds possessing promising coupling characteristics. A series of coupler 4-aryl-2-aminothiophene-3-carbonitrile derivatives were synthesized using Gewald’s reaction. The Gewald method, involves the reaction of ketones, aldehydes or 1,3-dicarbonyl species with activated nitriles and elemental sulfur in the presence of an amine base. Characterization of these coupling components was carried out by spectra analysis. The synthesized compounds were recrystallized, purified, characterized and evaluated for spectroscopic properties. They were found to possess good coupling properties as well as high degree of brightness and a colour deepening effect compared to other heterocyclic couplers