Phosphorus oxychloride → 2-chloro-3-phenylpyrazine

Reaction equation

[C:1]1([C:7]2[C:8](=O)[NH:9][CH:10]=[CH:11][N:12]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:8]1[C:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)=[N:12][CH:11]=[CH:10][N:9]=1

Participants

Reactant 2

HCID 24813Phosphorus oxychloride

HCID 1559662-Hydroxy-3-phenylpyrazine

Product 1

HCID 8246672-chloro-3-phenylpyrazine

Procedure

A 0.01 mol. sample of 3-phenylpyrazin-2(1H)one is mixed with 9.0 ml. of phosphorous oxychloride (POCl3) and refluxed for 5-6 hr. The excess phosphorous oxychloride is removed by distillation at reduced pressure and 25 ml. of methylene chloride added to the residue. The resultant solution is stirred with a few milliliters of ice water, dried, evaporated and the residue recrystallized to yield the title compound.

Workup

customThe excess phosphorous oxychloride is removed by distillation at reduced pressure and 25 ml
additionof methylene chloride added to the residue
customdried
customevaporated
customthe residue recrystallized

Sources & evidence

ORD record: ord-370af20a5193473586928eff3cc9b7e5
Source dataset: uspto-grants-1983_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04402958

Reaction notes

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