Reaktion #812994

Reaktionsgleichung

KBr

benzylmercaptan

15

anthranil

4-nitro 2-picoline-N-oxide

→

4-Benzylthio-2-picoline-N-oxide

Ausbeute 30.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeMineral oil was removed from potassium hydride (0.11M; 35 wt. % dispersion in mineral oil) by several washings with petroleum ether (5×50 ml)
2. 2
   SonstigeThe remaining petroleum ether was removed under vacuum
3. 3
   workup.ADDITIONTo this dry solid, 350 ml of anhydrous THF was added cautiously
4. 4
   TemperaturThe resultant milky white mixture was warmed to room temperature
5. 5
   workup.STIRRINGto stir for an additional 30 minutes
6. 6
   TemperaturThe mixture was then cooled to -30° C.
7. 7
   TemperaturOnce warmed to room temperature
8. 8
   Temperaturthe mixture was refluxed for one hour
9. 9
   TemperaturAt this time, the reaction was cooled to 0° C.
10. 10
    Sonstigequenched with 50 ml of water
11. 11
    Extraktionextracted with dichloromethane (3×300 ml)
12. 12
    TrocknenThe combined organic layers were dried (anhydrous Na2SO4)
13. 13
    Sonstigethe solvent was removed under reduced pressure
14. 14
    SonstigeThe crude residue was chromatographed on flash silica gel with MeOH/CH2Cl2 (Gradient: 3:97, 4:96, 5:95)
15. 15
    SonstigeThe pure product was isolated (6.94 g; 30% yield) as a tan solid

Vorschrift

Mineral oil was removed from potassium hydride (0.11M; 35 wt. % dispersion in mineral oil) by several washings with petroleum ether (5×50 ml). The remaining petroleum ether was removed under vacuum. To this dry solid, 350 ml of anhydrous THF was added cautiously. The well stirred suspension was cooled to 0° C. To this mixture, 14.1 ml (0.12 mol) of benzylmercaptan was added dropwise over a period of 30 minutes. The resultant milky white mixture was warmed to room temperature and allowed to stir for an additional 30 minutes. The mixture was then cooled to -30° C., and 15 41 g (0.1 mol) of 4-nitro 2-picoline-N-oxide was added portionwise. The mixture became dark orange-brown in color. Once warmed to room temperature, the mixture was refluxed for one hour. At this time, the reaction was cooled to 0° C. and quenched with 50 ml of water. The pH of the mixture was adjusted to approximately 6 with 2M HCl, and extracted with dichloromethane (3×300 ml). The combined organic layers were dried (anhydrous Na2SO4), and the solvent was removed under reduced pressure. The crude residue was chromatographed on flash silica gel with MeOH/CH2Cl2 (Gradient: 3:97, 4:96, 5:95). The pure product was isolated (6.94 g; 30% yield) as a tan solid: M.P. 98°-99° C.; IR (KBr) 3063, 3028, 1612, 1466, 1236, 831, 715, 675 cm-1 ; 1H NMR (CDCl3) δ 2.45 (s, 3H), 4.16 (s, 2H), 6.97 (dd, 1H, J=6.8, 2.7 Hz), 7.07 (d, 1H, J=2.7 Hz), 7.32 (m, 5H), 8.09 (d, 1H, J=6.8 Hz). Anal. Calcd. for C13H13NOS: C, 67.50; H, 5.66; N, 6.05; S, 13.86. Found: C, 67.51; H, 5.69; N, 6.08; S, 13.77.

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