Dedicated to Prof. W. Bruce Kover on the occasion of his 80th anniversary
A simple and efficient one-pot protocol has been developed for the synthesis of thiazole
derivatives from readily available starting materials. Tribromoisocyanuric acid was
successfully used for α-monohalogenation of β-keto esters in aqueous medium, which
in the presence of thiourea and DABCO produced the corresponding 2-aminothiazoles
in up to 87% yield. Extension of the reaction to thioacetamide and o-phenylenediamine led to 2-methylthiazole and quinoxalines, respectively. This approach
enables telescoping of the two steps into a single process.
Key words
heterocycles - condensation - thiazole - quinoxaline - green chemistry - tribromoisocyanuric
acid - pot-ecomomy - thiourea
