Diphenylacetic Acid → (S)-N-(1-(2-phenylethyl)pyrrolidin-3-yl)diphenylacetamide

Participants

Reaction Steps

Diphenylacetic acid (0.75 g) and (S)-3-amino-1-(2-phenylethyl)pyrrolidine (0.67 g) were dissolved in DMF (10 ml), and triethylamine (1.4 ml) was added thereto, which was followed by addition of diethyl cyanophosphate (0.67 ml) under ice-cooling. After completion of the reaction, the solvent was evaporated under reduced pressure. The obtained residue was dissolved in ethyl acetate, washed successively with an aqueous potassium carbonate solution and saturated brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the obtained residue was subjected to silica gel column chromatography (chloroform:methanol=30:1). The obtained eluate was concentrated to give (S)-N-(1-(2-phenylethyl)pyrrolidin-3-yl)diphenylacetamide (0.77 g). The obtained compound was dissolved in acetone (3 ml), and a solution of oxalic acid (0.18 g) in acetone (3 ml) was added thereto. The precipitated crystals were collected by filtration and washed with acetone to give (S)-N-(1-(2-phenylethyl)pyrrolidin-3-yl)diphenylacetamide oxalate, melting point 191-192° C.

Provenance & Evidence