Phosphorus oxychloride → 7-Bromo-2-chloroquinoxaline

HRID 927312

Reaction equation

HRID 927312 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([N:6]=[CH:7][C:8](=O)[NH:9]2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:15])=O>>[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

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 49132647-bromo-1H-quinoxalin-2-one

Product 1

HCID 49132537-Bromo-2-chloroquinoxalineYield 96%

Conditions

Temperature
100 °C

Procedure

7-bromo-2(1H)-quinoxalinone (47.2 g; 210 mmol) was added to phosphorus oxychloride (470 mL). The reaction mixture was stirred at 100° C. for 2 hours, cooled down to room temperature and evaporated to dryness. The crude product was taken up into DCM and poured onto ice, water and K2CO3 powder. The mixture was filtered over celite. The celite was washed twice with DCM. The organic layer was decanted, dried over MgSO4, filtered and evaporated to dryness to give 49 g (96%) of 7-bromo-2-chloro-quinoxaline (grey solid). MP=146° C.

Workup

  1. temperaturecooled down to room temperature
  2. customevaporated to dryness
  3. additionpoured onto ice, water and K2CO3 powder
  4. filtrationThe mixture was filtered over celite
  5. washThe celite was washed twice with DCM
  6. customThe organic layer was decanted
  7. dry with materialdried over MgSO4
  8. filtrationfiltered
  9. customevaporated to dryness

Sources & evidence

ORD record
ord-900f1ce6b0334475a5366b4cbf5f8352
Source dataset
uspto-grants-2016_03
Patent number
US09290478B2

Linked notes

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