Application
4-Bromoisothiazol is a pharmaceutical intermediate that can be prepared by one-step bromination of isothiazole and can be used to prepare Bcr-Abl1 kinase inhibitors.
Chemical Properties
White to off-white solid
Synthesis
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).
References
[1] Patent: WO2017/176961, 2017, A1. Location in patent: Paragraph 00375
[2] Journal of Medicinal Chemistry, 1968, vol. 11, # 1, p. 70 - 73
