反应详情

A mixture of the product from Step B (300 mg, 0.70 mmol) and 1.0 mL of acetic anhydride was warmed at reflux for 2.5 h. The solution was cooled to room temperature and concentrated under reduced pressure. The residue was partitioned between ethyl acetate and water, and the ethyl acetate layer was washed sequentially with saturated aqueous sodium bicarbonate solution and saturated aqueous brine, dried (magnesium sulfate) and concentrated under reduced pressure. The crude residue was purified by preparative thin-layer chromatography (silica gel, 7% methanol/dichloromethane) to afford the title compound as a pale yellow powder. LC/MS 301.9 (M+1).

1. temperaturewas warmed
2. temperatureat reflux for 2.5 h
3. concentrationconcentrated under reduced pressure
4. customThe residue was partitioned between ethyl acetate and water
5. washthe ethyl acetate layer was washed sequentially with saturated aqueous sodium bicarbonate solution and saturated aqueous brine
6. dry with materialdried (magnesium sulfate)
7. concentrationconcentrated under reduced pressure
8. customThe crude residue was purified by preparative thin-layer chromatography (silica gel, 7% methanol/dichloromethane)