4-Bromo-isothiazole

288-16-4

24340-77-0

General procedure for the synthesis of 4-bromoisothiazole from isothiazole: Bromine (12.5 g, 78.12 mmol) was added slowly and dropwise to a solution of isothiazole (5.0 g, 58.82 mmol) in acetic acid (37 mL) over a period of 20 min at 95 °C. The reaction mixture was stirred continuously at 95 °C for 6 h and subsequently cooled to room temperature. The cooled mixture was poured into ice water (100 mL). The resulting mixture was extracted with ether (200 mL x 2). The organic phases were combined and washed with 6N sodium hydroxide solution to pH 7-8, followed by drying with anhydrous sodium sulfate and filtration. The filtrate was concentrated under reduced pressure and the resulting residue was purified by distillation to give 4-bromoisothiazole as a white solid (1.5 g, 15% yield).