反应详情

Potassium phthalimide (4.60 g, 24.8 mmol) was added in four portions at 15-min intervals to a solution of 1,4-dibromo-2-butene (10.60 g, 49.5 mmol) in dimethylformamide (20 mL) and the resulting mixture was stirred overnight at room temperature. The mixture was concentrated under reduced pressure and the residue was partitioned between dichloromethane (25 mL) and 2N aqueous hydrochloric acid (25 mL). The aqueous layer was-extracted with dichloromethane (2×25 mL) and the organic layers were washed in succession with saturated aqueous sodium chloride (20 mL), dried (sodium sulfate), filtered, and evaporated. The crude product was purified by flash column chromatography silica gel (150 g) eluting with 50% dichlormethane/hexane increasing to 100% dichlormethane to yield 5.12 g (74% yield) of white crystalline product.

1. concentrationThe mixture was concentrated under reduced pressure
2. customthe residue was partitioned between dichloromethane (25 mL) and 2N aqueous hydrochloric acid (25 mL)
3. extractionThe aqueous layer was-extracted with dichloromethane (2×25 mL)
4. washthe organic layers were washed in succession with saturated aqueous sodium chloride (20 mL)
5. dry with materialdried (sodium sulfate)
6. filtrationfiltered
7. customevaporated
8. customThe crude product was purified by flash column chromatography silica gel (150 g)
9. washeluting with 50% dichlormethane/hexane increasing to 100% dichlormethane