Oxalic acid dihydrate → HCID 86744299, compound

Participants

Reaction Steps

To a solution of (2S, 4R)-2-[N-{2-(cyanoamino)ethyl}-N-(4-nitrobenzyloxycarbonyl)aminomethyl]-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.52 g) in acetone (30 ml) was added oxalic acid dihydrate (1.92 g) at ambient temperature. The mixture was stirred at the same temperature for 18 hours. Acetone was removed by evaporation to give a residue. A suspension of the syrup in ethyl acetate (100 ml) was washed in turn with 1N aqueous sodium hydroxide (50 ml×2), water (50 ml) and brine (50 ml), dried over magnesium sulfate and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (20 g) and eluted with a mixture of methanol and chloroform (2:98 v/v) to give (2S, 4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-[N-(4-nitrobenzyloxycarbonyl)-N-(2-ureidoethyl)aminomethyl]pyrrolidine (1.43 g).

Provenance & Evidence