Triphenylphosphine → (4S)-4-(acetylsulfanyl)pyrrolidin-2-one

Participants

Reaction Steps

20-(1) 15.6 g of triphenylphosphine were added to a suspension of 3 g of 4-hydroxy-2-pyrrolidinone in 200 ml of tetrahydrofuran, and then the mixture was stirred at room temperature for 5 minutes, after which it was cooled to -20° C. A solution of 9.3 ml of diethyl azodicarboxylate in 9 ml of tetrahydrofuran was added dropwise, whilst cooling at -12° C. to -20° C., to the previous solution. The mixture was then stirred at 0°-5° C. for 5 minutes, after which it was again cooled to -20° C. 4.2 ml of thioacetic acid were then added dropwise to the mixture, whilst cooling at -18° C. to -20° C. The mixture was then warmed to 0°-5° C. and stirred at that temperature for 2 hours. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure. The residue was purified first by column chromatography through silica gel, eluted with a 10:1 by volume mixture of ethyl acetate and methanol, and then by column chromatography through silica gel, eluted with a 2:1 by volume mixture of acetonitrile and benzene, to give 2.45 g of 4-acetylthio-2-pyrrolidinone as colorless crystals.

Provenance & Evidence