反应详情

An ethanol solution (4.0 mL) of potassium hydroxide (0.19 g) prepared under ice cooling was added to an ethanol (2.0 mL) solution of diethyl [(t-butoxycarbonyl)(methyl)amino]propanedioate (Intermediate 3-1, 1.0 g), and the mixture was stirred for 23 hours at room temperature. The reaction mixture was concentrated under reduced pressure, and a 1.0 mol/L-sodium hydrogen carbonate aqueous solution was added, followed by extracting the mixture with ethyl acetate. The aqueous layer was cooled with iced water, and potassium hydrogen sulfate was added to adjust it to pH 2, followed by extracting the mixture with chloroform. The extract was dried over anhydrous sodium sulfate, and the desiccant was filtered out. Then, the solvent was distilled off under reduced pressure to obtain N-(t-butoxycarbonyl)-O-ethyl-N-methyl-3-oxoserine (Intermediate 7-1, light yellow oil) (0.26 g, 29%).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. additiona 1.0 mol/L-sodium hydrogen carbonate aqueous solution was added
3. extractionby extracting the mixture with ethyl acetate
4. temperatureThe aqueous layer was cooled with iced water, and potassium hydrogen sulfate
5. additionwas added
6. extractionby extracting the mixture with chloroform
7. dry with materialThe extract was dried over anhydrous sodium sulfate
8. filtrationthe desiccant was filtered out
9. distillationThen, the solvent was distilled off under reduced pressure