反应详情

56.7 ml of trimethylbromosilane are added dropwise within a period of 15 minutes at 20° to a solution of 25.42 g of E-2-formylamino-4-methyl-5-diisopropylphosphono-3-pentenoic acid ethyl ester in 102 ml of dry dichloromethane. After stirring at room temperaturefor 20 hours, 102 ml of ethanol are added dropwise within a period of 15 minutes, and the whole is stirred for a further 20 hours. The clear reaction solution is then completely concentrated by evaporation in vacuo.The residue is concentrated by evaporation a further three times in each case after the addition of 100 ml of toluene. The oily residue is dissolved in 102 ml of ethanol, and a solution of 102 ml of propylene oxide in 102 ml of ethanol is added dropwise thereto. The product, obtained in crystalline form, is filtered off after 2 hours (room temperature) and washed with ethanol and ether. After drying (80°, 4 hours) under a high vacuum, E-2-amino-4-methyl-5 -phosphono-3-pentenoic acid ethyl ester is obtained in analytically pure form, m.p. 212° (decomp.).

1. stirringthe whole is stirred for a further 20 hours
2. concentrationThe clear reaction solution is then completely concentrated by evaporation in vacuo.The residue
3. concentrationis concentrated by evaporation a further three times in each case
4. additionafter the addition of 100 ml of toluene
5. dissolutionThe oily residue is dissolved in 102 ml of ethanol
6. additiona solution of 102 ml of propylene oxide in 102 ml of ethanol is added dropwise
7. customThe product, obtained in crystalline form
8. filtrationis filtered off after 2 hours (room temperature)
9. washwashed with ethanol and ether
10. customAfter drying (80°, 4 hours) under a high vacuum