Phosphorus oxychloride → 3-Chloroquinoxaline-6-carbonitrile

HRID 1019975Notes

Reaction equation

HRID 1019975 reaction equation
O=[C:2]1[NH:11][C:10]2[C:5](=[CH:6][CH:7]=[C:8]([C:12]#[N:13])[CH:9]=2)[N:4]=[CH:3]1.P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:2]1[CH:3]=[N:4][C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([C:12]#[N:13])=[CH:7][CH:6]=2

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 451217293-Hydroxyquinoxaline-6-carbonitrile

Product 1

HCID 738939393-Chloroquinoxaline-6-carbonitrileYield 79.4%

Procedure

A solution of 3-oxo-3,4-dihydro-quinoxaline-6-carbonitrile (5.99 g, 35 mmol, 1.0 eq) in phosphorus oxychloride (26 mL, 280 mmol, 8.0 eq) is heated under reflux for 1 hour. Then the reaction mixture is cooled down to room temperature and the solvent is evaporated. The residue is poured into ice water, the resulting mixture is neutralized with sodium carbonate and extracted with ethyl acetate (3×50 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a crude product that is purified by column chromatography (silica gel, eluent: dichloromethane 100%) to afford 3-chloro-quinoxaline-6-carbonitrile as a white solid (5.27 g, 79% yield).

Workup

  1. temperatureunder reflux for 1 hour
  2. customthe solvent is evaporated
  3. additionThe residue is poured into ice water
  4. extractionextracted with ethyl acetate (3×50 mL)
  5. dry with materialThe combined organic layers are dried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto give a crude product that
  9. customis purified by column chromatography (silica gel, eluent: dichloromethane 100%)

Sources & evidence

ORD record
ord-db0afa2bb5f740b793530584a14ebc49
Source dataset
uspto-grants-2014_05
Patent number
US08716280B2

Reaction notes

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