Ethanol → 1-Ethyl (3E)-2-amino-4-methyl-5-phosphono-3-pentenoate

Participants

Reaction Steps

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.).

Provenance & Evidence