反应详情

Borane dimethyl sulfide complex (2 M solution in THF, 0.414 mL, 0.828 mmol) was added at room temperature to a solution of 7-bromo-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one A-2 (100.0 mg, 0.414 mmol) in anhydrous THF (4.10 mL) under an atmosphere of argon. The reaction mixture was heated to reflux for 2 h, cooled to room temperature, quenched with methanol (1.0 mL), stirred for 30 mins and concentrated to dryness under reduced pressure. The crude residue was purified by flash column chromatography on silica gel (hexanes:ethyl acetate gradient) to give 7-bromo-2-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazine A-3 (92.9 mg, Yield=98%). MS (ESI) [M+1]+ 228, 230.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 2 h
3. customquenched with methanol (1.0 mL)
4. concentrationconcentrated to dryness under reduced pressure
5. customThe crude residue was purified by flash column chromatography on silica gel (hexanes:ethyl acetate gradient)