2-Bromothiazole, bromination preparation

All possible dichloro- or dibromothiazoles are known. The 2.5-dihalogeno derivatives can be prepared from the 5-halogeno-2-aminothiazoles by diazotization/decomposition with CuCl or CuBr (3, 12, 13, 18, 75). The 5-halogeno-2-aminothiazoles can be easily prepared by halogenation of 2-aminothiazole (65, 76-79) 2,5-dibromothiazole can also be prepared by direct bromination of 2-bromothiazole (5). 

Tervalent phosphorus acid esters, and triphenylphosphine, attack 2-bromothiazole (34) at bromine in alcoholic solvents to give thiazole and the oxidised phosphorus compounds. A similar attack of tris(diethylamino)phosphine on the bromine atom of bromopentafluorobenzene was used to prepare a series of main-group-four pentafluorophenyl derivatives, e.g. (35). A full paper has appeared on the fluoridation of trimethylsilyl phosphites, or phosphoramidites, with sulphury chloride fluoride. The mild conditions allowed the preparation of sensitive nucleoside derivatives, e.g. (36) and (37). 

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