反应详情

0.95 kg of ethyl 3-(ethoxycarbonylmethylamino)propionate (4.68 mol) was dissolved in 2.85 L of ethanol and 2.85 L of water. To this solution, 0.41 kg of sodium bicarbonate (4.91 mol) was added under stirring. Subsequently, 0.84 kg of benzylchloroformate (4.91 mol) was added dropwise at an internal temperature of 28 to 35° C. and the mixture was stirred at an internal temperature of 28 to 35° C. for 2 hours. Ethanol was evaporated under reduced pressure and 9.51 L of ethyl acetate was added. The mixture was then stirred for 5 minutes. The mixture was allowed to stand and the organic layer (top layer) was collected. To this layer, 4.8 L of water was added and the mixture was stirred for 5 minutes. The mixture was allowed to stand again and the organic layer (top layer) was collected. To this layer, 4.8 L of 28% brine was added and the mixture was stirred for 5 minutes. The mixture was allowed to stand again and the organic layer (top layer) was collected. To this layer, 0.57 kg of anhydrous sodium sulfate was added and the mixture was stirred for 1 hour. The solid was separated by filtration and washed with 0.95 L of ethyl acetate. The filtrate and the wash were combined and concentrated under reduced pressure. The resulting product was dried under reduced pressure at an external temperature of 50° C. for 30 minutes. This gave 1.64 kg of a crude product of the title compound as a colorless oil. This product was used in the subsequent step without further purification.

1. stirringthe mixture was stirred at an internal temperature of 28 to 35° C. for 2 hours
2. customEthanol was evaporated under reduced pressure and 9.51 L of ethyl acetate
3. additionwas added
4. stirringThe mixture was then stirred for 5 minutes
5. customthe organic layer (top layer) was collected
6. additionTo this layer, 4.8 L of water was added
7. stirringthe mixture was stirred for 5 minutes
8. customthe organic layer (top layer) was collected
9. additionTo this layer, 4.8 L of 28% brine was added
10. stirringthe mixture was stirred for 5 minutes
11. customthe organic layer (top layer) was collected
12. additionTo this layer, 0.57 kg of anhydrous sodium sulfate was added
13. stirringthe mixture was stirred for 1 hour
14. customThe solid was separated by filtration
15. washwashed with 0.95 L of ethyl acetate
16. concentrationconcentrated under reduced pressure
17. customThe resulting product was dried under reduced pressure at an external temperature of 50° C. for 30 minutes
18. customThis product was used in the subsequent step without further purification