Triethylamine → 1-[(2S,3S)-3-(N,N-Dibenzylamino)-2-hydroxy-4-phenylbutyryl]-N-t-butyl-L-prolinamide

Participants

Reaction Steps

14.0 g (37.0 mmol) of (2S, 3S)-3-(N,N-dibenzylamino)-2-hydroxy-4-phenylbutyric acid [prepared as described in step (a) above] and the whole of the N-t-butyl-L-prolinamide hydrochloride were suspended in 250 ml of methylene chloride, and 6.7 g (41.1 mmol) of diethyl cyanophosphate and 11.2 g (110.9 mmol) of triethylamine were slowly added dropwise to the suspension. The mixture was then stirred for 5 hours. At the end of this time, the reaction mixture was washed with a 10% w/v aqueous solution of citric acid, with a 10% w/v aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order. The mixture was then dried over anhydrous sodium sulfate, after which the solvent was removed by distillation under reduced pressure, and the resulting residue was recrystallized from hexane, to give 16.6 g of the title compound as colorless crystals, melting at 122°-123° C.

Provenance & Evidence