Phosphorus oxychloride → 2-Chloro-3-(4-methoxyphenyl)pyrazine

HRID 441724Notes

Reaction equation

HRID 441724 reaction equation
O[C:2]1[C:7]([C:8]2[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][CH:9]=2)=[N:6][CH:5]=[CH:4][N:3]=1.P(Cl)(Cl)([Cl:18])=O>>[Cl:18][C:2]1[C:7]([C:8]2[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][CH:9]=2)=[N:6][CH:5]=[CH:4][N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 1784889683-(4-Methoxyphenyl)pyrazin-2(1H)-one

Product 1

HCID 131998882-Chloro-3-(4-methoxyphenyl)pyrazine

Procedure

The 2-hydroxy-3-p-methoxyphenylpyrazine is refluxed (120°-130° C.) with excess phosphorus oxychloride under stirring for 3-5 hours. The solution is evaporated to dryness at 50° C. in vacuo, cooled, ice is added, then treated with 10% sodium hydroxide solution, extracted with a suitable solvent such as diethyl ether, the ethereal solution washed with water and evaporated. The crude product is crystallized from a suitable solvent such as ethanol to give 2-chloro-3-p-methoxyphenylpyrazine.

Workup

  1. customThe solution is evaporated to dryness at 50° C. in vacuo
  2. temperaturecooled
  3. additionice is added
  4. additiontreated with 10% sodium hydroxide solution
  5. extractionextracted with a suitable solvent such as diethyl ether
  6. washthe ethereal solution washed with water
  7. customevaporated
  8. customThe crude product is crystallized from a suitable solvent such as ethanol

Sources & evidence

ORD record
ord-8d2ff16741384b64953659517db8f22a
Source dataset
uspto-grants-1977_08
Patent number
US04042586

Reaction notes

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