反应详情

1.05 g of (R)-4-(p-methoxybenzoylamino)-2-hydroxy-butyric acid are boiled at reflux for 48 hours while stirring in 8.5 ml of trifluoroacetic acid anhydride and 0.2 g of sodium trifluoroacetate. After evaporation of the mixture, the residue is shaken twice with toluene and the toluene is then removed by evaporation in vacuo. The residue, containing (R)-1-(p-methoxybenzoyl)-2-oxo-3-pyrrolidinyl-trifluoroacetate, is boiled at reflux for 30 minutes in absolute methanol. After evaporation of the methanol, the residue is boiled in 400 ml of diisopropyl ether, the mixture is decanted, the solution is concentrated to 140 ml and then stirred at room temperature. The solid is filtered off and there is obtained (R)-1-(p-methoxybenzoyl)-3-hydroxy-2-pyrrolidinone of melting point 122.5°-123° C.; [α]D20 =+207°; [α]54620 =+256°; [α]36520 =+1172° (c=1.0 in chloroform).

1. temperatureat reflux for 48 hours
2. customAfter evaporation of the mixture
3. customthe toluene is then removed by evaporation in vacuo
4. additionThe residue, containing (R)-1-(p-methoxybenzoyl)-2-oxo-3-pyrrolidinyl-trifluoroacetate
5. temperatureat reflux for 30 minutes in absolute methanol
6. customAfter evaporation of the methanol
7. customthe mixture is decanted
8. concentrationthe solution is concentrated to 140 ml
9. stirringstirred at room temperature
10. filtrationThe solid is filtered off