Pyridine → 5-Chloropyrazine-2,3-dicarbonitrile

HRID 128376Notes

Reaction equation

HRID 128376 reaction equation
[C:1]([C:3]1[C:8]([C:9]#[N:10])=[N:7][C:6](O)=[CH:5][N:4]=1)#[N:2].S(Cl)([Cl:14])=O.N1C=CC=CC=1>>[C:1]([C:3]1[C:8]([C:9]#[N:10])=[N:7][C:6]([Cl:14])=[CH:5][N:4]=1)#[N:2]

Participants

4

Reactant 3

HCID 1049PyridineHCID 24386Thionyl ChlorideHCID 178510582HCID 178510582, compound

Product 1

HCID 129071975-Chloropyrazine-2,3-dicarbonitrileYield 77%

Procedure

2,3-Dicyano-5-hydroxypyrazine (7.30 g; 0.05 mole) was dissolved in 70 g (0.59 mole) of thionyl chloride, and the solution was cooled to 0° to 5° C. With stirring, 4.80 g (0.06 mole) of pyridine was added dropwise over the period of 15 minutes. Then, the mixture was stirred at 70° C. for 2 hours. After the reaction, the excess of thionyl chloride was distilled off under reduced pressure, and the residue was extracted with 150 ml of chloroform. The chloroform solution was washed twice with 50 ml of water, and dried over anhydrous calcium chloride, and then the solvent was distilled off to afford a red solid. Recrystallization of the solid from benzene afforded 6.30 g (yield 77%) of 2,3-dicyano-5-chloropyrazine.

Workup

  1. temperaturethe solution was cooled to 0° to 5° C
  2. stirringThen, the mixture was stirred at 70° C. for 2 hours
  3. customAfter the reaction
  4. distillationthe excess of thionyl chloride was distilled off under reduced pressure
  5. extractionthe residue was extracted with 150 ml of chloroform
  6. washThe chloroform solution was washed twice with 50 ml of water
  7. dry with materialdried over anhydrous calcium chloride
  8. distillationthe solvent was distilled off
  9. customto afford a red solid
  10. customRecrystallization of the solid from benzene

Sources & evidence

ORD record
ord-d5836fa4cbda469694f0058d63d5ae18
Source dataset
uspto-grants-1981_03
Patent number
US04259489

Reaction notes

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