Trifluoroacetic acid → (2S, 4S)-4-mercapto-2-[4-(N-4-nitrobenzyloxycarbonylacetimidoyl)piperazin-1-ylcarbonyl]-1-(4-nitrobenzyloxycarbonyl)pyrrolidine trifluoromethanesulfonate

Participants

Reaction Steps

3.2 ml of trifluoroacetic acid and 103 μl of trifluoromethanesulfonic acid were added to a solution of 430 mg of (2S,4S)-4-(4-methoxybenzylthio)-2-[4-(N-4-nitrobenzyloxycarbonylacetimidoyl)piperazin-1-ylcarbonyl]-1-(4-nitrobenzyloxycarbonyl)pyrrolidine [prepared as described in step (iii) above] in 636 μl of anisole, and the resulting mixture was stirred for 1 hour, whilst ice-cooling. An the end of this time, the reaction mixture was freed from the solvent by distillation under reduced pressure, and the residue was repeatedly washed with diethyl ether by decantation, to give 450 mg of the title compound, as a powder.

Provenance & Evidence