反应详情

A mixture of 17.0 g (44.5 mmol) of 18, 220 mL of 40% HBr, and 440 mL of glacial acetic acid was refluxed for 10 hr, and then additionally stirred for 12 hr at room temperature. To the resulting mixture 2000 mL of water and 500 mL of dichloromethane were added. The organic layer was separated, and the aqueous layer was extracted with 2×200 mL of dichloromethane. The combined organic extract was washed with saturated aqueous NaHCO3, dried over K2CO3, and then evaporated to dryness. This procedure gave 15.7 g (97%) of 19 which was further used without an additional purification.

1. temperaturewas refluxed for 10 hr
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with 2×200 mL of dichloromethane
4. extractionThe combined organic extract
5. washwas washed with saturated aqueous NaHCO3
6. dry with materialdried over K2CO3
7. customevaporated to dryness