反应详情

To a stirred solution of 4-bromo-2-chlorobenzoic acid (4.27 g, 18.1 mmol) in tetrahydrofuran (39 mL) at 0° C. is added borane-tetrahydrofuran complex (1 M in THF) (36.3 mL, 36.3 mmol). The reaction mixture is stirred 16 h at room temperature. At 0° C., water is slowly added then NaHCO3 aq. sat. is also slowly added The resulting solution is extracted with EtOAc (3×50 mL). The combined organic layer is washed with brine, dried over anhydrous MgSO4, filtered and concentrated under reduced pressure. The crude product is purified by flashchromatography (eluent: Hexanes/EtOAc 85:15 to 70:30) to provide the expected product (4-bromo-2-chlorophenyl)methanol (4.34 g, 108%). 1H NMR (300 MHz, CHLOROFORM-D): δ 7.53 (1H, d, J=1.8 Hz), 7.43 (1H, dd, J=8.2, 1.8 Hz), 7.38 (1H, d, J=8.2 Hz), 4.74 (2H, d, J=6.2 Hz), 1.90 (1H, t, J=6.3 Hz).

1. extractionis extracted with EtOAc (3×50 mL)
2. washThe combined organic layer is washed with brine
3. dry with materialdried over anhydrous MgSO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe crude product is purified by flashchromatography (eluent: Hexanes/EtOAc 85:15 to 70:30)