Phosphorus oxychloride → 7-Bromo-2-chloroquinoxaline

HRID 711363Notes

Reaction equation

HRID 711363 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([N:6]=[CH:7][C:8](O)=[N:9]2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:15])=O>CN(C=O)C>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([N:6]=[CH:7][C:8]([Cl:15])=[N:9]2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178516705HCID 178516705, compound

Product 1

HCID 49132537-Bromo-2-chloroquinoxalineYield 93%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideCatalyst

Conditions

Temperature
100 °C

Procedure

To the suspension of 7-bromoquinoxalin-2-ol (2 g, 8.88 mmol) in neat phosphorus oxychloride (7 mL) was added DMF (2 drops). The mixture was heated to 100° C. for 3 h. Then it was cooled to room temperature. Phosphorus oxychloride was removed under vacuum, and the residue was dissolved into EtOAc and dropped into ice water with stirring. The mixture was extracted with EtOAc for three times, the combined organic layer was washed with saturated NaHCO3 solution. Then the organic layer was concentrated to afford 7-bromo-2-chloroquinoxaline as a solid in 93% yield (2 g).

Workup

  1. temperatureThen it was cooled to room temperature
  2. customPhosphorus oxychloride was removed under vacuum
  3. dissolutionthe residue was dissolved into EtOAc
  4. additiondropped into ice water
  5. extractionThe mixture was extracted with EtOAc for three times
  6. washthe combined organic layer was washed with saturated NaHCO3 solution
  7. concentrationThen the organic layer was concentrated

Sources & evidence

ORD record
ord-fd3b037881a242e096a036135ef61d3c
Source dataset
uspto-grants-2015_11
Patent number
US09181264B2

Reaction notes

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