反应详情

To a stirred solution of 4-bromo-1-(bromomethyl)-2-chlorobenzene (7.19 g, 25.3 mmol) in dichloromethane (60 mL) and water (60 mL) is added tetrabutylammonium bromide (0.82 g, 2.53 mmol). Potassium cyanide (4.94 g, 75.8 mmol) in water (60 mL) is then added. The resulting solution is stirred 4 h at room temperature and quickly turned orange. A saturated solution of NaHCO3 aq. is then added and the mixture extracted with CH2Cl2 (3×100 mL). The combined organic layer is washed with brine, dried over anhydrous MgSO4 and filtered on a silica gel pad. The pad is rinsed with CH2Cl2 and the filtrate concentrated under reduced pressure to provide the expected product 2-(4-bromo-2-chlorophenyl)acetonitrile (5.38 g, 92%) contaminated with bromoform. 1H NMR (300 MHz, CHLOROFORM-D): δ 7.60 (1H, d, J=1.9 Hz), 7.47 (1H, dd, J=8.3, 1.9 Hz), 7.39 (1H, d, J=8.3 Hz), 3.79 (2H, s).

1. extractionthe mixture extracted with CH2Cl2 (3×100 mL)
2. washThe combined organic layer is washed with brine
3. dry with materialdried over anhydrous MgSO4
4. filtrationfiltered on a silica gel pad
5. washThe pad is rinsed with CH2Cl2
6. concentrationthe filtrate concentrated under reduced pressure