Reaktion #171237

ord-875e3d173bb9491faad5cf74d30f8873

Reaktionsbedingungen

Temperatur
0°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.STIRRINGstirred at 0° C. for 20 minutes
  2. 2
    workup.STIRRINGstirring
  3. 3
    Sonstigewas continued at 0° C
  4. 4
    workup.WAITAfter 3 hours
  5. 5
    Sonstigethe reaction was quenched with the drop-wise addition of saturated ammonium chloride solution, and dichloromethane
  6. 6
    workup.ADDITIONwas added
  7. 7
    SonstigeThe organic layer was separated
  8. 8
    Extraktionthe aqueous layer was extracted with dichloromethane
  9. 9
    WaschenThe organic layer was washed with brine
  10. 10
    Trocknendried over anhydrous sodium sulphate
  11. 11
    Einengenconcentrated under reduced pressure
  12. 12
    SonstigeThe crude product thus obtained
  13. 13
    Sonstigewas purified by silica gel flash column chromatography

Vorschrift

In a flame-dried flask, 3-{3-[(4S)-4-benzyl-2-oxo-1,3-thiazolidin-3-yl]-3-oxopropyl}-1,2,3-benzotriazin-4(3H)-one (0.25 g) was taken up in dichloromethane (10 mL) and cooled to 0° C. Titanium tetrachloride (0.76 mL, 1 M solution) was added drop-wise and the reaction mixture was stirred for 10 to 15 minutes. (−)-Sparteine (0.36 mL) was added slowly to the reaction mixture and stirred at 0° C. for 20 minutes. A solution of the compound obtained from step e above (0.17 g) in dichloromethane (10 mL) was added slowly, and stirring was continued at 0° C. After 3 hours, the reaction was quenched with the drop-wise addition of saturated ammonium chloride solution, and dichloromethane was added. The organic layer was separated and the aqueous layer was extracted with dichloromethane. The organic layer was washed with brine, dried over anhydrous sodium sulphate, and concentrated under reduced pressure. The crude product thus obtained was purified by silica gel flash column chromatography using 30% ethyl acetate in hexane as eluant to afford the title compound (0.2 g).

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08846910B2uspto-grants-2014_09