Synthesis and solvent characteristics of bishetaryl monoazo dyes derived from polysubstituted-2-aminothiophene derivatives

The synthesis of two series of some new bishetaryl monoazo dyes from diazotized 3,5-disubstituted-4-methyl-2-aminothiophene derivatives and 4-aryl-2-aminothiazole and 4-aryl-3-cyano-2-aminothiophene derivatives as coupling components, respectively, is described. Characterization of these dyes was carried out by spectral and elemental analyses. The visible absorption maxima of dyes shift large bathochromic in basic organic solvent with high polarity (dimethylformamide) relative to corresponding solvent with low polarity (chloroform). The behavior of acid-base properties of these dyes in various organic solvents via visible absorption spectra characteristics was also evaluated.