4-Nitrobenzyl chloroformate → HCID 22881641, compound

Participants

Reaction Steps

0.51 g of 4-dimethylaminopyridine was added dropwise at room temperature to a solution of 1.83 g of (2S,4S)-4-(4-methoxybenzylthio)-2-(2-methylpiperazin-1-yl-carbonyl)-2-(4-nitrobenzyloxycarbonyl)pyrrolidine [prepared as described in step (ii) above] in 25 ml of dry acetonitrile, and then a solution of 0.90 g of 4-nitrobenzyl chloroformate in 15 ml of dry acetonitrile was added dropwise to the resulting mixture, whilst ice-cooling. The reaction mixture was stirred at room temperature for 30 minutes, after which it was concentrated by evaporation under reduced pressure, and the residue was diluted with ethyl acetate. The diluted solution was washed with water and with an aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through silica gel, using a 7:3 by volume mixture of ethyl acetate and cyclohexane as the eluent, to give 2.28 g of the title compound, as an amorphous solid.

Provenance & Evidence