Synthesis
2-Chloro-6-methylphenol (5 g, 35 mmol) was used as starting material and dissolved in acetic acid (70 mL). Subsequently, N-bromosuccinimide (NBS, 6.2 g, 35 mmol) was added to this solution. The reaction mixture was stirred at room temperature for 12 hours. After completion of the reaction, the acetic acid was removed by distillation under reduced pressure. The residue was diluted with ethyl acetate, washed sequentially with saturated sodium carbonate solution and dried over sodium sulfate. Finally, the solvent was removed by reduced pressure distillation to afford the target product 4-bromo-2-chloro-6-methylphenol (4 g, 52% yield), which can be used in subsequent reactions without further purification.
References
[1] Patent: WO2017/4609, 2017, A1. Location in patent: Paragraph 0219
[2] Heterocycles, 1993, vol. 36, # 7, p. 1483 - 1488
[3] Patent: US2008/146595, 2008, A1. Location in patent: Page/Page column 24
[4] Patent: WO2017/4608, 2017, A1. Location in patent: Paragraph 0142
[5] European Journal of Medicinal Chemistry, 2017, vol. 127, p. 944 - 957
