Phosphorus oxychloride → 2-Chloro-7-fluoro-8-methylquinoxaline

HRID 2233166Notes

Reaction equation

HRID 2233166 reaction equation
[F:1][C:2]1[C:11]([CH3:12])=[C:10]2[C:5]([N:6]=[CH:7][C:8](=O)[NH:9]2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:8]1[CH:7]=[N:6][C:5]2[C:10](=[C:11]([CH3:12])[C:2]([F:1])=[CH:3][CH:4]=2)[N:9]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 451217207-Fluoro-8-methyl-2(1H)-quinoxalinone

Product 1

HCID 866283592-Chloro-7-fluoro-8-methylquinoxalineYield 65%

Procedure

7-Fluoro-8-methyl-2(1H)-quinoxalinone (5.75 g, 32.3 mmol) in phosphorus oxychloride (30 ml) was heated under reflux for 2 h. Phosphorus oxychloride was removed by evaporation, and the residue was basified with aqueous sodium bicarbonate and extracted several times with ethyl acetate. The extracts were dried and evaporated, and the residue was dissolved in dichloromethane and passed quickly through a short column of silica (20 g), washing through with more dichloromethane. Removal of solvent gave product (4.13 g, 65%).

Workup

  1. temperatureunder reflux for 2 h
  2. customPhosphorus oxychloride was removed by evaporation
  3. extractionextracted several times with ethyl acetate
  4. customThe extracts were dried
  5. customevaporated
  6. dissolutionthe residue was dissolved in dichloromethane
  7. washwashing through with more dichloromethane
  8. customRemoval of solvent

Sources & evidence

ORD record
ord-f488b29e33a24bdbb12b3a1b9acb6e33
Source dataset
uspto-grants-2010_05
Patent number
US07709483B2

Reaction notes

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