Triethylamine → (2S, 4R)-2-(carbamoylmethyloxymethyl)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine

Participants

Reaction Steps

A solution of isobutyl chloroformate (0.60 g) in tetrahydrofuran (1 ml) was dropwise added to a solution of (2S,4R)-2-(carboxymethyloxymethyl)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.28 g) and triethylamine (0.82 ml) in tetrahydrofuran (13 ml) at -10°~-5° C., and the mixture was stirred at the same temperature for 30 minutes. The mixture was dropwise added to concentrated ammonia water (10 ml) at 0°-5° C. and the solution was stirred at the same temperature for 1 hour. The mixture was poured into water (50 ml) and extracted with chloroform (50 ml). The organic layer was dried over magnesium sulfate and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (25 g) and eluted with a mixture of methanol and chloroform (2:98 V/V) to give (2S,4R)-2-(carbamoylmethyloxymethyl)4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.00 g).

Provenance & Evidence