(2S,4S)-4-(4-methoxybenzyl)thio-1-(4-nitrobenzyloxycarbonyl)-L-proline → Diisopropylethylamine

Participants

Reaction Steps

To a solution of (2S,4S)-4-(4-methoxybenzyl)thio-1-(4-nitrobenzyloxycarbonyl)-L-proline (5.38 g) in anhydrous acetonitrile (70 ml), N,N'-carbonyldiimidazole (2.04 g) was added, followed by stirring at room temperature for one hour. To the reaction mixture, N,N-diisopropylethylamine (2.0 ml) and a solution of the compound (11.00 g), which had been obtained in (2), in anhydrous acetonitrile (35 ml) were added and the mixture was reacted overnight at room temperature. The reaction mixture was concentrated by evaporation under reduced pressure. Ethyl acetate was added to the residue. The resulting mixture was washed with water and saturated saline, dried over anhydrous magnesium sulfate and then concentrated by evaporation under reduced pressure. The residue was purified by chromatography (ethyl acetate-methanol) through a silica gel column, whereby the title target compound (10.09 g) was obtained as an amorphous substance.

Provenance & Evidence