反应详情

A solution of 53.9 g of ethyl N-(ethoxycarbonylmethyl)-N-(ethoxycarbonyl)-β-alaninate in 200 ml of toluene is added dropwise to a stirred solution of potassium hexamethyldisilazide (429 ml, 0,653M) in 125 ml of toluene under nitrogen and cooled to 0°. After 45 minutes at 0°, 21.6 ml of acetic acid is added followed by a solution of 100 g of sodium phosphate (monobasic) in 1 liter of water. The layers are separated, the organic layer is washed with pH 7 buffer, dried over sodium sulfate, filtered, concentrated and purified by flash chromatography using ethyl acetate/hexane (3:7) to yield ethyl 1-ethoxycarbonyl-3-oxo-pyrrolidine-2-carboxylate.

1. temperaturecooled to 0°
2. customThe layers are separated
3. washthe organic layer is washed with pH 7 buffer
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. custompurified by flash chromatography