反应详情

Twenty-eight grams of dihydro-1H-pyrrolizine-3,5 (2H,6H)-dione (III) are dissolved in 100 g of ethyl alcohol and 0.2 ml of concentrated hydrochloric acid is added. The solution is heated at reflux for 104 hours. The mixture is cooled and excess ethyl alcohol is distilled at reduced pressure. The oil is dissolved in 1 l of anhydrous diethylether, 1 g of activated charcoal is added and the resulting suspension is filtered through filter aid. The filtrate is concentrated at reduced pressure and the resulting crystals are isolated by filtration. Recrystallization from carbon tetrachloride-petroleum ether yields 5-oxo-2-pyrrolidinepropanoic acid ethyl ester with a melting point of 60°-61° C.

1. temperatureThe solution is heated
2. temperatureat reflux for 104 hours
3. temperatureThe mixture is cooled
4. distillationexcess ethyl alcohol is distilled at reduced pressure
5. dissolutionThe oil is dissolved in 1 l of anhydrous diethylether
6. addition1 g of activated charcoal is added
7. filtrationthe resulting suspension is filtered
8. filtrationthrough filter aid
9. concentrationThe filtrate is concentrated at reduced pressure
10. customthe resulting crystals are isolated by filtration
11. customRecrystallization from carbon tetrachloride-petroleum ether