Реакция #44982

Уравнение реакции

Pyrazine-2-carbonitrile

sulfuryl chloride

→

title compound

Выход 47.4%

3-Chloropyrazine-2-carbonitrile

Выход 47.4%

Растворители

toluene

N,N-dimethylformamide

Условия реакции

Обработка

1. 1
   Температураcooling
2. 2
   workup.ADDITIONAfter completion of addition
3. 3
   ДругоеThe toluene layer is separated
4. 4
   Экстракцияthe residual red oil is extracted with diethyl ether
5. 5
   Температураcooled with ice
6. 6
   workup.ADDITIONafter pouring
7. 7
   workup.ADDITIONby adding saturated aqueous sodium hydrogen carbonate solution
8. 8
   ДругоеThe organic layer is separated
9. 9
   Экстракцияaqueous layer is extracted with diethyl ether
10. 10
    Промывкаwashed with water
11. 11
    Сушкаdried over sodium sulfate
12. 12
    Другоеevaporated
13. 13
    Другоеto remove the solvent under reduced pressure
14. 14
    ДругоеThe resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1)

Методика

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).

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