Synthesis, Spectroscopic Studies and Technical Evaluation of Novel Disazo Disperse Dyes Derived from 3-(2-hydroxyphenyl)-2-pyrazolin-5-ones for Dyeing Polyester Fabrics

摘要

In one of our projects, on disperse dye, we were interested in the synthesis, tautomeric structures and evaluation of pyrazolin-5-one azodyes with better dyeing properties. In this regard novel bisazo-pyrazolin-5-one dyes 3a-f were synthesized via coupling of the select diazotizated p -nitroaniline with4-arylhydrazono-3-(2`-hydroxyphenyl)-2-pyrazolin-5-ones 2a-f. On further treatment of these products 3a-f with acetic anhydride in the presence of p -toluenesulfonic acid furnished the corresponding diacetylpyrazolone derivatives 4a-f . A combination of spectral evidence and acetylation reaction provided a coherent picture of compounds under scrutiny is best described as the azo-hydrazone tautomeric form (A _(24 )) as the Z,E -configuration. Finally, two series of the synthesized dyes 3a-f and 4a-f 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.