New synthetic strategy for novel 6-arylazo-5-methyl-3-aryl-thiazolo[2,3-c]- [1,2,4]triazoles and study of their solvatochromic properties

Two series of 6-arylazothiazol[2,3- c ][1,2,4]triazoles were prepared via oxidative cyclization of the respective aldehyde N-(5-arylazo-4-methylthiazol-2-yl)-hydrazones. The structures of the latter hydrazone precursors and the azo compounds were confirmed by spectral and elemental analyses. The solvatochromism of the title azo dyes is evaluated by means of the Kamlet–Taft equation and discussed.