Sulfuryl chloride → 3-Chloropyrazine-2-carbonitrile

HRID 2109052Notes

Reaction equation

HRID 2109052 reaction equation
[N:1]1[CH:6]=[CH:5][N:4]=[CH:3][C:2]=1[C:7]#[N:8].S(Cl)([Cl:12])(=O)=O>C1(C)C=CC=CC=1.CN(C)C=O>[Cl:12][C:3]1[C:2]([C:7]#[N:8])=[N:1][CH:6]=[CH:5][N:4]=1

Participants

5

Reactant 2

HCID 24648Sulfuryl chlorideHCID 73172Pyrazinecarbonitrile

Product 1

HCID 2924653-Chloropyrazine-2-carbonitrileYield 47.4%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6228DimethylformamideSolvent

Procedure

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).

Workup

  1. temperaturecooling
  2. additionAfter completion of addition
  3. customThe toluene layer is separated
  4. extractionthe residual red oil is extracted with diethyl ether
  5. temperaturecooled with ice
  6. additionafter pouring
  7. additionby adding saturated aqueous sodium hydrogen carbonate solution
  8. customThe organic layer is separated
  9. extractionaqueous layer is extracted with diethyl ether
  10. washwashed with water
  11. dry with materialdried over sodium sulfate
  12. customevaporated
  13. customto remove the solvent under reduced pressure
  14. customThe resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1)

Sources & evidence

ORD record
ord-ddd1c44ae986410a8db99d85561b7ba8
Source dataset
uspto-grants-2009_04
Patent number
US07514449B2

Reaction notes

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