反应详情

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.

1. temperatureafter which it was cooled to -20° C
2. temperaturewhilst cooling at -12° C. to -20° C., to the previous solution
3. stirringThe mixture was then stirred at 0°-5° C. for 5 minutes
4. temperatureafter which it was again cooled to -20° C
5. temperaturewhilst cooling at -18° C. to -20° C
6. temperatureThe mixture was then warmed to 0°-5° C.
7. stirringstirred at that temperature for 2 hours
8. concentrationAt the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure
9. customThe residue was purified first by column chromatography through silica gel
10. washeluted with a 10:1 by volume mixture of ethyl acetate and methanol
11. washby column chromatography through silica gel, eluted with a 2:1 by volume mixture of acetonitrile and benzene