Pivaloyl chloride → HCID 67881956, compound

Participants

Reaction Conditions

Reaction Steps

2.60 g of (2S,4S)-4-(4-methoxybenzylthio)-1-(4-nitrobenzyloxycarbonyl)-2-pyrrolidinecarboxylic acid were dissolved in 20 ml of dry tetrahydrofuran, and the resulting solution was cooled to -20° C. 590 mg of triethylamine and then 704 mg of pivaloyl chloride were added to the solution, after which the resulting mixture was stirred at the same temperature for 5 minutes. 2100 g of (3R)-3-dimethylaminopyrrolidine trifluoroacetate, 788 mg of diisopropylethylamine and 20 ml of dry acetonitrile were then added, in that order, to the mixture, and the mixture was gradually heated and then stirred at 0° C. for 1 hour. The reaction mixture was then filtered, and the solvent was removed by evaporation under reduced pressure. The residue was diluted with ethyl acetate, and the diluted solution was washed with an aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order. It was then dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by silica gel column chromatography, using a 3:1 by volume mixture of acetonitrile and methanol as the eluent, to obtain 2.56 g of the title compound as a powder.

Provenance & Evidence