反应详情

Sodium hydride (95%, 1.78 g, 83 mmol) and dimethyl sulfoxide (DMSO) (150 mL) were combined under argon in a 3-neck 1L round bottom flask. A solution of Compound 3 in DMSO (50 mL) was added dropwise over 0.75 h using an addition funnel. After stirring an additional 0.5 h, methyl bromoacetate (7.9 mL, 83 mmol) in DMSO (50 mL) was added dropwise. After 18 h, the contents of the reaction flask were poured into water. Saturated sodium bicarbonate was added and the resulting solution was extracted several times with ethyl acetate. The combined organic extracts were washed successively with water and brine. The organic layer was dried with anhydrous sodium sulfate then concentrated in vacuo to give an oil. Purification by flash column chromatography (hexane:ethyl acetate 70:30) afforded Compound 4 as an oil: 24.6 g (64 mmol, 100%)

1. waitAfter 18 h
2. extractionthe resulting solution was extracted several times with ethyl acetate
3. washThe combined organic extracts were washed successively with water and brine
4. dry with materialThe organic layer was dried with anhydrous sodium sulfate
5. concentrationthen concentrated in vacuo
6. customto give an oil
7. customPurification by flash column chromatography (hexane:ethyl acetate 70:30)