反应详情

Absolute ethanol (300 mL) was cooled at −5° C. then thionyl chloride (14.01 mL, 192.1 mmol) was added keeping the temperature below 0° C., followed by portionwise addiction of (S)-6-oxopiperidine-2-carboxylic acid (25.0 g, 174.6 mmol). The mixture was stirred at room temperature for 6 hours. The solvent was evaporated, then toluene (300 mL) and Et3N (48.7 mL) were added. After 0.5 hour the precipitate was filtered and washed with toluene and Et2O. The filtrate was evaporated and the residue treated with Et2O. The precipitate was eliminated and the solution was concentrated to give the title compound as yellow oil. Yield (29.9 g, 100%).

1. customthe temperature below 0° C.
2. customThe solvent was evaporated
3. additiontoluene (300 mL) and Et3N (48.7 mL) were added
4. filtrationAfter 0.5 hour the precipitate was filtered
5. washwashed with toluene and Et2O
6. customThe filtrate was evaporated
7. additionthe residue treated with Et2O
8. concentrationthe solution was concentrated