Diisopropylethylamine → (4-nitrophenyl)methyl N-[4-[(2S,4S)-4-[(4-methoxyphenyl)methylsulfanyl]-1-methylpyrrolidine-2-carbonyl]piperazine-1-carboximidoyl]carbamate

Participants

Reaction Conditions

Reaction Steps

480 mg of (2S,4S)-4-(4-methoxybenzylthio)-1-methylpyrrolidine-2-carboxylic acid were suspended in 20 ml of dry acetonitrile, and 325 mg of N,N'-carbonyldiimidazole were added to this suspension, after which the mixture was stirred at 40° C. for 1 hour. At the end of this time, the reaction mixture was cooled with ice, and 980 mg of 1-(4-nitrobenzyloxycarbonylamidino)piperazine bis(trifluoroacetate) [prepared as described in step (a) above] and 320 μl of diisopropylethylamine were added to the mixture, which was then stirred at room temperature overnight. At the end of this time, the reaction mixture was diluted with ethyl acetate and washed with an aqueous solution of sodium hydrogen-carbonate, with water (4 times) and with an aqueous solution of sodium chloride, in that order. The ethyl acetate solution was dried over anhydrous sodium sulfate and then concentrated by evaporation under reduced pressure. The resulting residue was subjected to silica gel column chromatography, eluted with a 4:1 by volume mixture of ethyl acetate and methanol. The fraction containing the desired compound was concentrated by evaporation under reduced pressure, to obtain 860 mg of the title compound, as a powder.

Provenance & Evidence