반응 #5215

ord-68f86829b5d7433a974d30f73e142209

반응 조건

상세 조건
See reaction.notes.procedure_details.

후처리

  1. 1
    온도after which it was cooled to -20° C
  2. 2
    온도whilst cooling at -12° C. to -20° C., to the previous solution
  3. 3
    workup.STIRRINGThe mixture was then stirred at 0°-5° C. for 5 minutes
  4. 4
    온도after which it was again cooled to -20° C
  5. 5
    온도whilst cooling at -18° C. to -20° C
  6. 6
    온도The mixture was then warmed to 0°-5° C.
  7. 7
    workup.STIRRINGstirred at that temperature for 2 hours
  8. 8
    농축At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure
  9. 9
    기타The residue was purified first by column chromatography through silica gel
  10. 10
    세척eluted with a 10:1 by volume mixture of ethyl acetate and methanol
  11. 11
    세척by column chromatography through silica gel, eluted with a 2:1 by volume mixture of acetonitrile and benzene

실험 절차

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.

출처

DOI: 10.6084/m9.figshare.5104873.v1특허: US05242914uspto-grants-1993_09