反应详情

To a solution of 3,8-dibromo-benzo[c]chromen-6-one (650 mg, 1.85 mmol) in THF (20 mL) was added 2 M solution of LiBH4 in THF (3.7 mL, 7.4 mmol). The mixture was stirred for 3 hours at room temperature. Quenched slowly with ammonium chloride solution. The mixture was extracted with ethyl acetate, dried over Na2SO4, filtered and concentrated in vacuo. The obtained residue was suspended in 85% phosphoric acid (20 mL) and heated at 160° C. for 4 h. The mixture was extracted with ethyl acetate, washed with water, dried over Na2SO4, filtered and concentrated in vacuo. The obtained residue was purified by flash chromatography to provide the desired product 3,8-Dibromo-6H-benzo[c]chromene as a white solid (539 mg, 86%).

1. customQuenched slowly with ammonium chloride solution
2. extractionThe mixture was extracted with ethyl acetate
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. temperatureheated at 160° C. for 4 h
7. extractionThe mixture was extracted with ethyl acetate
8. washwashed with water
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customThe obtained residue was purified by flash chromatography