Phosphorus oxychloride → 3-Chloro-6-methoxypyrazin-2-amine

HRID 441736Notes

Reaction equation

HRID 441736 reaction equation
[NH2:1][C:2]1[CH:7]=[N+:6]([O-])[CH:5]=[C:4]([O:9][CH3:10])[N:3]=1.P(Cl)(Cl)([Cl:13])=O>>[NH2:1][C:2]1[C:7]([Cl:13])=[N:6][CH:5]=[C:4]([O:9][CH3:10])[N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 205289822-Amino-6-methoxypyrazine 4-oxide

Product 1

HCID 117010873-Chloro-6-methoxypyrazin-2-amine

Procedure

A suspension of 2-amino-6-methoxypyrazine 4-oxide in freshly distilled phosphorus oxychloride is refluxed for one hour. Thin layer chromatography indicates that the starting material is no longer present. The excess of phosphorus oxychloride is removed in vacuo and the residue is treated with crushed ice. If decomposition is complete the solution is made alkaline with 10% sodium hydroxide and extracted with chloroform. The chloroform extracts are washed with water, dried over sodium sulfate and evaporated to give the product which may be recrystallized from a suitable solvent such as ethanol.

Workup

  1. temperatureis refluxed for one hour
  2. customThe excess of phosphorus oxychloride is removed in vacuo
  3. additionthe residue is treated with crushed ice
  4. extractionextracted with chloroform
  5. washThe chloroform extracts are washed with water
  6. dry with materialdried over sodium sulfate
  7. customevaporated
  8. customto give the product which
  9. custommay be recrystallized from a suitable solvent such as ethanol

Sources & evidence

ORD record
ord-d21f8adf8297470da7103afcdb971758
Source dataset
uspto-grants-1977_08
Patent number
US04042586

Reaction notes

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