Propylene Oxide → HCID 86746443, compound

Participants

Reaction Steps

E-2-methylamino-4-methyl-5-phosphono-3-pentenoic acid (3) 20 ml of trimethylbromosilane are added dropwise at 20° within a period of 10 minutes under argon to a solution of 9.50 g of E-2-(N-methylformylamino)-4-methyl-5-diisopropylphosphono-3-pentenoic acid ethyl ester in 40 ml of dry dichloromethane. After stirring at room temperature for 20 hours, 37 ml of ethanol are added dropwise within a period of 15 minutes, and the who)e is stirred for a further 20 hours. The clear reaction solution is then concentrated to dryness by evaporation in vacuo. The residue is concentrated by evaporation twice more in each case after the addition of 30 ml of toluene. 128 ml of 2 N hydrochloric acid are added to the resulting oil, and the mixture is stirred at a bath temperature of 85° for 16 hours. The reaction mixture is concentrated by evaporation in vacuo. Concentration by evaporation twice after the addition of ethanol/toluene 1:1 yields an oily residue, which is dissolved in 51 ml of ethanol and to which there is added dropwise a solution of 51 ml of propylene oxide in 51 ml of ethanol. The product obtained in crystalline form is filtered off after 2 hours and recrystallised from water/ethanol. In this manner there is obtained E-2-methylamino-4-methyl-5-phosphono-3-pentenoic acid, m.p. 239° (decomp.).

Provenance & Evidence