635723-84-1

3-Fluoro-2-methylbenzonitrile (50 g, 0.37 mol) was used as starting material and dissolved in carbon tetrachloride (500 mL). Subsequently, N-bromosuccinimide (NBS, 72.5 g, 0.408 mol) and azobisisobutyronitrile (AIBN, 1.2 g, 0.037 mol) were added to this solution. The reaction mixture was heated to reflux overnight and the progress of the reaction was monitored by thin layer chromatography (TLC), and after confirming the completion of the reaction, the reaction solution was filtered. The filtrate was concentrated under vacuum to obtain the crude product. The crude product was purified by fast silica gel column chromatography with the eluent of petroleum ether/ethyl acetate (500:1), resulting in the target compound 2-cyano-6-fluorobenzyl bromide (2B, 30 g, 40% yield) as a white solid.

[1] Patent: US2012/129836, 2012, A1. Location in patent: Page/Page column 12
[2] Patent: WO2013/45607, 2013, A1. Location in patent: Page/Page column 29
[3] Patent: WO2016/202253, 2016, A1. Location in patent: Page/Page column 161