Trifluoroacetic acid → (2S,4S)-4-Mercapto-2-{4-[2-(4-nitrobenzyloxycarbonyl)oxyethyl]-1-piperazinylcarbonyl}-1-(4-nitrobenzyloxycarbonyl)pyrrolidine bis(trifluoromethanesulfonate)

Participants

Reaction Steps

135.75 mg of trifluoroacetic acid and 6.18 ml of trifluoromethanesulfonic acid were added, whilst ice-cooling, to a solution of 26.00 g of (2S,4S)-4-(4-methoxybenzylthio)-2-{4-[2-(4-nitrobenzyloxycarbonyl)oxyethyl]-1-piperazinylcarbonyl}-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (prepared as described in Preparation 14) in 38.8 ml of anisole, and the resulting mixture was stirred at the same temperature for 1.5 hours. At the end of this time, the solvent was removed by distillation under reduced pressure, and the resulting residue was washed with diethyl ether by repeated decantation and dried under reduced pressure to give 32.5 g of the title compound as a powder.

Provenance & Evidence