Cook–Heilbron thiazole synthesis

The Cook–Heilbron thiazole synthesis highlights the formation of 5-aminothiazoles through the chemical reaction of α-aminonitriles or aminocyanoacetates with dithioacids, carbon disulphide, carbon oxysulfide, or isothiocyanates at room temperature and under mild or aqueous conditions. Variation of substituents at the 2nd and 4th position of the thiazole is introduced by selecting different combinations of starting reagents.

This reaction was first discovered in 1947 by Alan H. Cook, Sir Ian Heilbron, and A.L Levy, and marks one of the first examples of 5-aminothiazole synthesis with significant yield and diversity in scope. Prior to their discovery, 5-aminothiazoles were a relatively unknown class of compounds, but were of synthetic interest and utility. Their premier publication illustrated the formation of 5-amino-2-benzylthiazole and 5-amino-4-carbethoxy-2-benzylthiazole by reacting dithiophenylacetic acid with aminoacetonitrile and ethyl aminocyanoacetate, respectively. Subsequent experiments by Cook and Heilbron, detailed in their series of publications titled “Studies in the Azole Series” describe early attempts to expand the scope of 5-aminothiazole synthesis, as well as employ 5-aminothiazoles in the formation of purines and pyridines.