反应详情

To a solution of 5,7-difluoro-2,3-dihydro-4H-chromen-4-one (14.2 g, 77.0 mmol, US 20050038032) in methanol (200 mL) was added sodium borohydride (3.50 g, 92.5 mmol) at 0° C. The reaction mixture was stirred at the same temperature for 1 hour, and evaporated to remove methanol. The residue was quenched with water, and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, and concentrated in vacuum. The residue was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1 as an eluent) to afford the title compound as a pale gray solid (9.64 g, 67%).

1. customevaporated
2. customto remove methanol
3. customThe residue was quenched with water
4. extractionextracted with ethyl acetate
5. washThe extract was washed with brine
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated in vacuum
8. customThe residue was purified by column chromatography on silica gel (hexane