反应详情

To a solution of 6-bromo-2-o-tolyl-chroman-4-ol (11.9 g, 37.3 mmol) in dichloromethane (130 ml) at 0° C. triethylsilane (29.6 g, 255 mmol, 6.8 eq) and trifluoroacetic acid (75 ml, 27 eq) were added. The solution was stirred at room temperature for 2.5 h. The solvent was removed under reduced pressure and the residue separated between water and ethyl acetate. The aqueous layer was extracted with ethyl acetate and the combined organic layers washed with water and saturated aqueous solution of sodium hydrogencarbonate, dried with sodium sulfate and filtered, and the solvent removed under reduced pressure. The crude product was purified by column chromatography (silica gel; ethyl acetate/heptane gradient). 6-Bromo-2-o-tolyl-chroman was obtained as a pale yellow oil (7.10 g, 63%).

1. customThe solvent was removed under reduced pressure
2. customthe residue separated between water and ethyl acetate
3. extractionThe aqueous layer was extracted with ethyl acetate
4. washthe combined organic layers washed with water and saturated aqueous solution of sodium hydrogencarbonate
5. dry with materialdried with sodium sulfate
6. filtrationfiltered
7. customthe solvent removed under reduced pressure
8. customThe crude product was purified by column chromatography (silica gel; ethyl acetate/heptane gradient)