Hydrochloric Acid → L-homoalanin-4-yl(methyl)phosphinic acid hydrochloride

Participants

Reaction Steps

0.0087 g (0.019 mmol) of chloronorbornadienerhodium(I) dimer and 0.022 g (0.053 mmol) of the compound Va are dissolved in 5 ml of methanol under an atmosphere of argon. The catalyst solution obtained is added under argon to a solution of 2.21 g (0.01 mol) of 2-acetamido-4-(hydroxymethylphosphinyl)-2-butenoic acid in 45 ml of methanol. The reaction vessel is evacuated, then hydrogenation is performed at a pressure of 3.0 bar. After a reaction time of 44 hours, the reaction vessel is depressurized, the reaction mixture evaporated down, the residue taken up in water and the precipitated catalyst separated off. As a result of adding an equivalent quantity of concentrated hydrochloric acid to the filtrate, a 6N hydrochloric acid solution is prepared which is boiled under reflux for 12 hours. After evaporating this solution down, 2.0 g (91.9% of theory) of L-homoalanin-4-yl(methyl)phosphinic acid hydrochloride is obtained as a white solid which is purified by recrystallization from an ethanol/water mixture.

Provenance & Evidence