1,1'-Carbonyldiimidazole → Diisopropylethylamine

Participants

Reaction Steps

To a solution of (2S,4S)-4-(4-methoxybenzyl)thio-1-(4-nitrobenzyloxycarbonyl)-L-proline (909 mg) in anhydrous acetonitrile (13 ml), N,N-carbonyldiimidazole (346 mg) was added, followed by stirring at room temperature for 30 minutes. To the reaction mixture, N,N-diisopropylethylamine (338 μl) and a solution of the compound (1.68 g), which had been obtained in (2), in anhydrous acetonitrile (15 ml) were added and the mixture was stirred overnight at room temperature. Dichloromethane was added to the reaction mixture. The resulting mixture was washed with water and saturated saline, dried over anhydrous magnesium sulfate and concentrated by evaporation under reduced pressure. The residue was purified by chromatography through a silica gel column (ethyl acetate-methanol), whereby 1.88 g of the title target compound were obtained as a colorless amorphous substance.

Provenance & Evidence