Synthesis and spectral properties of some azo disperse dyes containing a benzothiazole moiety

Abstract

A known method was employed for the preparation of four substituted benzothiazole amines I–IV in moderate yields. These heterocyclic amines were diazotized with nitorsyl sulfuric acid and subsequently coupled with N,N-diethyl aniline and N-phenyl-2, 2′-iminodiethanol to afford heteroarylazo amine dyes 1–8 in satisfactory yields. These dyes were characterized by UV–Visible, FT-IR, 1H NMR, and elemental analysis techniques. The solvatochromism behavior of the azo compounds is investigated by studying their spectra in pure and mixed organic solvents of different characteristics. The color of the dyes is discussed with respect to the nature of the heterocyclic ring and substituent present therein. In addition, effects of acid and base on the visible absorption maxima of the dyes are also reported.