Potassium Carbonate → Benzyl L-prolinate

Participants

Reaction Steps

1-[(S)-2-[[[1-(Benzoyloxy)-2-phenylethyl]hydroxyphosphinyl]oxy]-1-oxo-6-[[(phenylmethoxy)carbonyl]amino]hexyl]-L-proline, phenylmethyl ester from Example 5(d) is suspended in dry dimethylformamide and treated with chloromethylpivalate. After several hours, additional chloromethylpivalate and anhydrous potassium carbonate are added and the resulting mixture is stirred overnight. The mixture is then diluted with ethyl acetate and washed successively with water, 5% potassium bisulfate, saturated sodium bicarbonate, and saturated sodium chloride solution, dried (Na2SO4), and evaporated. The residue is purified by flash chromatography (silica gel) to give 1-[(S)-2-[[[(2,2-dimethyl-1-oxopropoxy)methoxy][1-(benzoyloxy)-2-phenylethyl]phosphinyl]oxy]-1-oxo]-6-[[(phenylmethoxy)carbonyl]amino]hexyl]-L-proline, phenylmethyl ester.

Provenance & Evidence