Ethyl 3-amino-2-(4-methoxyphenyl)propyl(diethoxymethyl)phosphinate → 3-Amino-2-(4-methoxyphenyl)propylphosphonous acid

Participants

Reaction Steps

A solution of 4.6 g of ethyl 3-amino-2-(4-methoxyphenyl)propyl(diethoxymethyl)phosphinate in 30 ml of 36% aqueous hydrochloric acid is heated to reflux for a period of 1 hour. The reaction mixture is then allowed to cool to room temperature, concentrated under reduced pressure and co-evaporated twice with 20 ml of water under reduced pressure. The crude product is dissolved in 20 m l of water, washed twice with 20 ml of diethyl ether and the aqueous layer is then separated and evaporated under reduced pressure. The crude product is dissolved in 50 ml ethanol and 5 ml of propylene oxide is added dropwise. The precipitated solid is collected by filtration and dried to give 3-amino-2-(4-methoxyphenyl)propylphosphonous acid (1/2 M H2O), m.p. 260°-265° C., 31 p=+24.5 ppm (D2O).

Provenance & Evidence