反应详情

2-Fluoro-5-methoxybenzonitrile (3d, purchased from Alfa Aesar) (5 g, 33 mmol) was dissolved in hydrobromic acid (50 mL) and glacial acetic acid (30 mL), refluxed for 28 hours at 140° C., and then the reaction mixture was diluted with 100 mL ethyl acetate. The reaction mixture was then washed with 50 mL water and saturated sodium chloride solution successively for three times. The organic layers were combined and concentrated to give a crude product of 2-fluoro-5-hydroxybenzoic acid (3e), 2.88 g white solid (yield 56%). 1H NMR (600 MHz, DMSO-d6) δ 7.19-7.17 (m, 1H), 7.08-7.04 (m, 1H), 6.95-6.92 (m, 1H); ESI-MS m/z: calculated for 156.02. found 154.91 [M−H]+.

1. washThe reaction mixture was then washed with 50 mL water and saturated sodium chloride solution successively for three times
2. concentrationconcentrated