反应详情

温度

-78 °C

Add anhydrous dichloromethane (400 mL) to 2-(4-methoxy-phenyl)-2-methyl-propionitrile (11.93 g, 68.1 mmol) and cool to −78° C. under nitrogen. Then add boron tribromide (33.0 mL, 349 mmol) and stir at −78° C. for 30 minutes. Remove the dry ice/acetone bath and allow the reaction to warm to room temperature. Stir for 3 h and then pour the reaction onto ice. Extract with ethyl acetate (2× 150 mL), dry the extracts over magnesium sulfate, filter, and concentrate on a rotary evaporator to give the crude product. The crude product is purified by flash chromatography on silica gel eluting with 35% ethyl acetate/hexanes to yield 9.79 g (89%) of 2-(4-hydroxy-phenyl)-2-methyl-propionitrile: TLC: Rf in 40% ethyl acetate/hexanes: 0.38; 1H NMR (CDCl3): 7.34-7.32 (m, 2H), 6.86-6.83 (m, 2H), 5.23 (s, 1H), 1.70 (s, 6H).

1. customRemove the dry ice/acetone bath
2. customthe reaction
3. temperatureto warm to room temperature
4. additionpour
5. customthe reaction onto ice
6. extractionExtract with ethyl acetate (2× 150 mL)
7. dry with materialdry the extracts over magnesium sulfate
8. filtrationfilter
9. concentrationconcentrate on a rotary evaporator
10. customto give the crude product
11. customThe crude product is purified by flash chromatography on silica gel eluting with 35% ethyl acetate/hexanes