Synthesis
General procedure for the synthesis of 3-bromo-2-chloroaniline from 1-bromo-2-chloro-3-nitrobenzene: A mixed solution of 1-bromo-2-chloro-3-nitrobenzene (2.7 g, 11.44 mmol) and SnCl2 (12.97 g, 57.20 mmol) in ethanol (60 mL) was stirred and reacted for 3 hr under reflux conditions. Upon completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched with deionized water followed by extraction with ethyl acetate. The organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography with the eluent ratio of ethyl acetate/petroleum ether=1:50 to afford the target product 3-bromo-2-chloroaniline as an off-white solid (1.3 g, 55.2% yield).
References
[1] Patent: WO2017/15562, 2017, A1. Location in patent: Page/Page column 101
[2] Patent: WO2017/211303, 2017, A1. Location in patent: Page/Page column 30
[3] Patent: WO2015/54572, 2015, A1. Location in patent: Page/Page column 271
[4] Patent: EP1847541, 2007, A1. Location in patent: Page/Page column 72
[5] Patent: US2011/52578, 2011, A1
