反应详情

温度

0 °C

In a 2 l three necked flask fitted with mechanical stirrer and reflux condenser, under inert atmosphere, a solution of 133 g (583 mmoles, 1 eq) of (2S)-2-(4-methoxycarbonyl-2-oxo-1-pyrrolidinyl)butanamide 11 in 200 ml of EtOH is added to 300 ml of EtOH, and the mixture cooled down to 0° C. 66.2 g (1.74 mole, 12 eq) of solid NaBbe are then added by portions over 1.5 hour, all the while maintaining the temperature between 2 and 4° C. After 2 hours, the temperature is raised to 12° C. for 1 hour, and lowered again to 24° C. 240 ml of a saturated solution of NH4Cl are added dropwise over 1 hour, followed by 120 ml of acetone, and the mixture is left overnight at room temperature. The mixture is filtered, the precipitate washed with 3×70 ml of EtOH and the combined organic fractions concentrated to dryness to give 148 g of crude 6. It is suspended in 300 ml of CH2Cl2 and stirred for 30 min, filtered, washed with 2×100 ml of CH2Cl2 and dried to give 114 g of pure 6, 98%.

1. temperaturereflux condenser
2. temperatureall the while maintaining the temperature between 2 and 4° C
3. temperaturethe temperature is raised to 12° C. for 1 hour
4. customlowered again to 24° C
5. waitthe mixture is left overnight at room temperature
6. filtrationThe mixture is filtered
7. washthe precipitate washed with 3×70 ml of EtOH
8. concentrationthe combined organic fractions concentrated to dryness
9. customto give 148 g of crude 6
10. filtrationfiltered
11. washwashed with 2×100 ml of CH2Cl2
12. customdried
13. customto give 114 g of pure 6, 98%