反应详情

To a solution of 2-bromo-5-chlorobenzoic acid (5.49 g, 23.3 mmol) in anhydrous THF (70 mL) under nitrogen was added dropwise a BH3 THF solution (1.0 M, 55 mL) at 0° C. and the reaction mixture was stirred overnight at room temperature. Then the mixture was cooled on an ice bath and MeOH (20 mL) was added dropwise to decompose excess BH3. The resulting mixture was stirred until no bubble was released and then 10% NaOH (10 mL) was added. The mixture was concentrated and the residue was mixed with water (200 mL) and extracted with EtOAc. The residue from rotary evaporation was purified by silica gel column chromatography (5:1 hexane/EtOAc) to give 2-bromo-5-chlorobenzyl alcohol as a white solid (4.58 g, 88%): 1H NMR (300 MHz, DMSO-d6): δ (ppm) 7.57 (d, J=8.7 Hz, 1H), 7.50-7.49 (m, 1H), 7.28-7.24 (m, 1H), 5.59 (t, J=6.0 Hz, 1H), 4.46 (d, J=6.0 Hz, 2H).

1. temperatureThen the mixture was cooled on an ice bath
2. stirringThe resulting mixture was stirred until no bubble
3. concentrationThe mixture was concentrated
4. additionthe residue was mixed with water (200 mL)
5. extractionextracted with EtOAc
6. customThe residue from rotary evaporation
7. customwas purified by silica gel column chromatography (5:1 hexane/EtOAc)