2‐(2‐Hydroxyphenyl)‐5‐aminothiazoles: Synthesis and Properties Involving Dual Emissions

2‐(2‐Hydroxyphenyl)‐5‐aminothiazoles were prepared by two different methods to elucidate their photophysical properties. The first synthetic method involved the addition of thioamide dianions derived from secondary thioamides and nBuLi to thioforamides. Alternatively, Pd‐catalyzed sequential addition of aromatic groups and diarylamines to commercially available thiazoles led to the precursors of the desired thiazoles. The molecular structures of the resulting thiazoles were determined by X‐ray analyses. The thiazoles showed dual‐emission in cyclohexane and in the solid state. Dual or nothing: Dual‐emissive 2‐(2‐hydroxyphenyl)‐5‐aminothiazoles were designed and prepared by two different methods. Thioamide dianions were the key species to lead to 4‐phenyl‐5‐aminothiazoles. Sequential functionalization of commercially available thiazoles led to 4‐methylthiazoles. X‐ray structure analyses of the 2‐(2‐hydroxy)phenyl)‐5‐aminothiazole implied that it induces excited state intramolecular proton transfer. Dual emission was observed in cyclohexane and in the solid state.