反应详情

95.6 g (340 mmol) of 2-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-yl]-acetic acid ethyl ester are dissolved in 440 ml of methanol; 22.5 g (40 mmol) of potassium hydroxide (80% strength) are added and the whole is heated under reflux for 16 hours. Concentration by evaporation is carried out under reduced pressure at 70°, 200 ml of hydrochloric acid are added and the whole is extracted by shaking with 800 ml of ethyl acetate. The organic phase is washed with saturated sodium chloride solution, concentrated to 500 ml, and 200 ml of hexane are added. The crystalline precipitate is filtered off with suction and dried. 2-[4-(p-chlorophenyl)-2-oxopyrrolidin-1-yl]-acetic acid having a melting point of 142°-43° is obtained. Additional product can be obtained by concentrating the mother liquor by evaporation, taking up the residue in 200 ml of ethyl acetate and crystallising it by the addition of 100 ml of hexane.

1. temperaturethe whole is heated
2. temperatureunder reflux for 16 hours
3. concentrationConcentration
4. customby evaporation
5. customis carried out under reduced pressure at 70°
6. addition200 ml of hydrochloric acid are added
7. extractionthe whole is extracted
8. washThe organic phase is washed with saturated sodium chloride solution
9. concentrationconcentrated to 500 ml, and 200 ml of hexane
10. additionare added
11. filtrationThe crystalline precipitate is filtered off with suction
12. customdried