Acetic Anhydride → 2-Acetamido-5-bromo-1,3-thiazole

Participants

Reaction Steps

To a solution of 2-amino-5-bromothiazole (22.3 g, 85.9 mmol) in methylene chloride (100 mL) and pyridine (60 mL) was added acetic anhydride (11 mL) slowly with stirring. The mixture was allowed to stir for 2.5 hours, warmed to room temperature, and stirred for an additional 4 hours. Most of the solvent was removed in vacuo and the residue was washed with ethyl acetate and aqueous HCl. The organic solution was then washed with water, dried over MgSO4 and concentrated to give a crude solid. This solid was triturated with Et2O, filtered, washed with Et2O, and dried to give 2-acetamido-5-bromothiazole as a solid (15.1 g, 80%, C5H5BrN2OS, MS m/e 222 (M+H)+).

Provenance & Evidence