Reaktion #51620

Reaktionsgleichung

DEAD

2-anilino-6-quinoxalinol

(S)-(+)-3-hydroxytetrahydrofuran

triphenylphosphine

→

Phenyl-[6-(tetrahydrofuran-3-(R)-yl-oxy)quinoxalin-2-yl]amine

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe mixture is concentrated
2. 2
   Sonstigepartitioned between EtOAc and H2O
3. 3
   WaschenThe organic layer is washed with H2O, brine
4. 4
   Trocknendried (MgSO4)
5. 5
   Einengenconcentrated
6. 6
   SonstigeThe resulting yellow oil is chromatographed (50% EtOAc/hexanes)
7. 7
   workup.ADDITIONHCl/Et2O solution is added dropwise
8. 8
   Sonstigethe resulting red-orange powder is dried in vacuo
9. 9
   workup.STIRRINGby stirring in MeOH
10. 10
    Waschenwith washed (3×H2O, 5×MeOHM basic ion exchange resin
11. 11
    workup.STIRRINGThe mixture is stirred 30 minutes
12. 12
    Filtrationfiltered
13. 13
    Einengenconcentrated
14. 14
    Sonstigerecrystallized from EtOAc/hexanes
15. 15
    Sonstigeto provide, in two crops

Vorschrift

To a THF solution at 0° C. under argon is added 2-anilino-6-quinoxalinol (0.23 g, 0.97 mmol), (S)-(+)-3-hydroxytetrahydrofuran (0.086 mL, 1.3 mmol), and triphenylphosphine (0.31 g, 1.2 mmol). DEAD (0.18 mL, 1.2 mmol) is added portionwise. The reaction is allowed to warm to room temperature and stirred for 1.5 hours. The mixture is concentrated and partitioned between EtOAc and H2O. The organic layer is washed with H2O, brine, dried (MgSO4), and concentrated. The resulting yellow oil is chromatographed (50% EtOAc/hexanes) and taken up in Et2O/IPA. HCl/Et2O solution is added dropwise and the resulting red-orange powder is dried in vacuo. The powder is free-based by stirring in MeOH with washed (3×H2O, 5×MeOHM basic ion exchange resin. The mixture is stirred 30 minutes, filtered, concentrated, and recrystallized from EtOAc/hexanes to provide, in two crops, the product (m.p. 173-175° C.). Anal. Calcd. for C18H17N3O2: C, 70.35; H, 5.57; N, 13.67; Found: C, 70.19; H, 5.60; N, 13.66.

Quelle