Hydrochloric Acid → Ethyl 3-amino-3-(4-chlorophenyl)propyl(diethoxymethyl)phosphinate

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Reaction Steps

To a solution of 25.4 g of ethyl 2-(4-chlorobenzoyl)ethyl(diethoxymethyl)phosphinate in 200 ml of methanol is added 52 g of ammonium acetate and 4.23 g of sodium cyanoborohydride. The mixture is stirred under an atmosphere of nitrogen at room temperature for a period of 3 days. The mixture is then acidified to pH 2 with the requisite amount of dilute hydrochloric acid and the methanol is evaporated under reduced pressure. The crude product is dissolved in 25 ml of water, washed twice with 20 ml of diethyl ether and the aqueous layer is then made alkaline to pH 12 with potassium hydroxide. The solution is then saturated with sodium chloride and extracted with 3×25 ml of dichloromethane. The organic phase is dried over magnesium sulphate and then evaporated under reduced pressure to give ethyl 3-amino-3-(4-chlorophenyl)propyl(diethoxymethyl)phosphinate as a viscous oil, 31P=45.9 ppm (CDCl3).

Provenance & Evidence