A series of azo disperse dyes were synthesized by coupling reaction of N, N-diethylaniline, 2- anilinoethanol and N-phenyl-2, 2′-iminodiethanol with diazotized aminothiazolyl derivatives as diazo components. These dyes have been prepared in good yields, and were characterized by UV–Vis, FT-IR and 1H NMR spectroscopic techniques. The effects of solvent polarity and various pH on dyes in the visible absorption spectra were evaluated. ...