Synthesis, Structure Elucidation and Application of Some New Azo Disperse Dyes Derived from 4-Hydroxycoumarin for Dyeing Polyester Fabrics

As a part of our ongoing interest in disperse dyes and task specific azo dyes with better dyeing properties, we synthesized a series of 3-aryl(hetaryl)hydrazono-2,4-chromandiones 4a-kvia Coupling of 4-hydroxycoumarin with diazotized aniline derivatives. Structures of the synthesized compounds have been investigated by means of UV, IR, 1H-NMR and mass spectroscopy in order to elucidate their tautomeric and isomeric structures. The results of such spectral data indicated that compounds 4a-k exist predominantly in the hydrazo structure (D) as a mixture of Z and E-isomer with ratio ~ 84.5:15.5. Finally, the prepared dyestuffs 4a-k were applied as disperse dyes for dyeing polyester fabrics and their fastness properties were evaluated. Also, the position of color in CIELAB coordinates (L*, a*, b*, H*, C* and K/S) estimated and discussed.