反应详情

A solution of 1.20 g of E-2-isopropylamino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester hydrochloride in 7 ml of water is stirred under reflux for 20 hours. The reaction mixture is concentrated to dryness by evaporation in vacuo. Ethanol is added to the residue, and the mixture is again concentrated by evaporation. This process is repeated twice more. The residue is dissolved in 25 ml of ethanol, a total of 5 ml of propylene oxide is added dropwise thereto with stirring, and the whole is concentrated to dryness by evaporation. The residue is dissolved in a little water, and ethanol is added until the solution becomes cloudy. The solution is stirred at room temperature for 4 hours to complete the reaction, during which time crystallisation slowly takes place. The product is filtered off, washed with ethanol and diethyl ether and dried at 100° under a high vacuum. In this manner there is obtained E-2-isopropylamino-4-methyl-5-phosphono-3-pentenoic acid, m.p. 225°-227° (decomp.).

1. temperatureunder reflux for 20 hours
2. concentrationThe reaction mixture is concentrated to dryness by evaporation in vacuo
3. additionEthanol is added to the residue
4. concentrationthe mixture is again concentrated by evaporation
5. dissolutionThe residue is dissolved in 25 ml of ethanol
6. additiona total of 5 ml of propylene oxide is added dropwise
7. concentrationthe whole is concentrated to dryness by evaporation
8. dissolutionThe residue is dissolved in a little water, and ethanol
9. additionis added until the solution
10. stirringThe solution is stirred at room temperature for 4 hours
11. customthe reaction
12. customduring which time crystallisation slowly takes place
13. filtrationThe product is filtered off
14. washwashed with ethanol and diethyl ether
15. customdried at 100° under a high vacuum