反应详情

To a stirred solution of 4-bromo-3-methyl benzonitrile (5 g, 25.5 mmol) in CCl4 (200 mL), was added N-bromosuccinimide (4.99 g, 28.05 mmol) and 2,2-Azobisisobutyronitrile (335 mg, 2.04 mmol). The mixture was heated to reflux overnight then cooled, diluted with CH2Cl2 and quenched with 10% NaHSO3. The layers were separated and the CH2Cl2 layer was washed with saturated NaHCO3 and brine, dried over MgSO4, filtered and concentrated under vacuum. Column chromatography on silica gel (5-10% ethyl acetate/hexanes) afforded 4.31 g (3.65 mmol, 61%) of a mixture of mono- and di-bromo intermediates. 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 4.55 (s, 2H) 7.42 (dd, J=8.31, 2.01 Hz, 1H) 7.67-7.78 (m, 2H). Mass spec.: 275.94 (MH)+.

1. temperatureThe mixture was heated
2. temperatureto reflux overnight
3. temperaturethen cooled
4. customquenched with 10% NaHSO3
5. customThe layers were separated
6. washthe CH2Cl2 layer was washed with saturated NaHCO3 and brine
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated under vacuum