Reaktion #44982

Reaktionsgleichung

Pyrazine-2-carbonitrile

sulfuryl chloride

→

title compound

Ausbeute 47.4%

3-Chloropyrazine-2-carbonitrile

Ausbeute 47.4%

Lösungsmittel

toluene

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling
2. 2
   workup.ADDITIONAfter completion of addition
3. 3
   SonstigeThe toluene layer is separated
4. 4
   Extraktionthe residual red oil is extracted with diethyl ether
5. 5
   Temperaturcooled with ice
6. 6
   workup.ADDITIONafter pouring
7. 7
   workup.ADDITIONby adding saturated aqueous sodium hydrogen carbonate solution
8. 8
   SonstigeThe organic layer is separated
9. 9
   Extraktionaqueous layer is extracted with diethyl ether
10. 10
    Waschenwashed with water
11. 11
    Trocknendried over sodium sulfate
12. 12
    Sonstigeevaporated
13. 13
    Sonstigeto remove the solvent under reduced pressure
14. 14
    SonstigeThe resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1)

Vorschrift

Pyrazine-2-carbonitrile (26.36 g) is dissolved in toluene (187 ml)/N,N-dimethylformamide (19 ml), and thereto is added dropwise sulfuryl chloride (135 g) under ice-cooling. After completion of addition, the reaction solution is warmed to room temperature gradually and stirred overnight. The toluene layer is separated and the residual red oil is extracted with diethyl ether. The organic layers are combined, cooled with ice, and after pouring thereto ice-water, neutralized by adding saturated aqueous sodium hydrogen carbonate solution. The organic layer is separated, and aqueous layer is extracted with diethyl ether. The organic layers are combined, washed with water, dried over sodium sulfate and evaporated to remove the solvent under reduced pressure. The resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1) to give the title compound (16.58 g).

Quelle