Synthesis
General procedure for the synthesis of 6-bromo-2-benzothiazolinone from 2-hydroxybenzothiazole: Bromine (5.1 mL, 99.2 mmol) was slowly added dropwise to a solution of 3H-benzothiazol-2-one (7) (5 g, 33.1 mmol) in dichloromethane (DCM) (200 mL). The reaction mixture was stirred at room temperature for 3 hours. After completion of the reaction, the precipitate was collected by filtration, washed with ether and dried to give the target compound 8 as a white powder (6.85 g, 90% yield). Compound 8 had the molecular formula C7H4BrNOS, molecular weight of 230.1 g/mol, and melting point of 229-231 °C. 1H NMR (300 MHz, CDCl3) data were as follows: δ 7.03 (d, 1H, J = 8.9 Hz), 7.43 (dd, 1H, J = 1.7 Hz, 8.9 Hz), 7.85 (d, 1H, J = 1.7 Hz). Mass spectra (ESI+) showed m/z 229.8 [M + H79Br]+ and 231.7 [M + H81Br]+.
References
[1] Journal of Heterocyclic Chemistry, 1988, vol. 25, p. 1503 - 1509
[2] European Journal of Medicinal Chemistry, 2017, vol. 137, p. 310 - 326
[3] Monatshefte fur Chemie, 2011, vol. 142, # 1, p. 67 - 80
[4] European Journal of Medicinal Chemistry, 2015, vol. 92, p. 807 - 817
[5] Bollettino Scientifico della Facolta di Chimica Industriale di Bologna, 1944, vol. 5, p. 11,14, 16, 18
