反应详情

To a solution of the compound of Example (a) (12.1 g, 0.52 mol) in CH2Cl2 (200 mL) was added 1.0 M boron tribromide in CH2Cl2 (2.2 eq, 115 mL) at 0°. The reaction was stirred at 0° for 20 min, then at ambient temperature for 2.5 h. The reaction was then cooled to 0°, and quenched by the slow addition of methanol. The solvents were removed under reduced pressure and the trimethyl borate was removed by azeotropation with added methanol. Vacuum drying yielded a dark green-brown solid (11.51 g, 100%) which was used without further purification: MS (ES) m/z 217.2. (M+H)+.

1. waitat ambient temperature for 2.5 h
2. temperatureThe reaction was then cooled to 0°
3. customquenched by the slow addition of methanol
4. customThe solvents were removed under reduced pressure
5. customthe trimethyl borate was removed by azeotropation with added methanol
6. customVacuum drying