Phosphorus oxychloride → 2-Chloro-6,7-difluoro-3-styrylquinoxaline

HRID 584661Notes

Reaction equation

HRID 584661 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[F:12])[NH:8][C:7](=O)[C:6]([CH:14]=[CH:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[N:5]2.O=P(Cl)(Cl)[Cl:24]>CN(C)C1C=CN=CC=1>[Cl:24][C:7]1[C:6]([CH:14]=[CH:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[N:5][C:4]2[C:9](=[CH:10][C:11]([F:12])=[C:2]([F:1])[CH:3]=2)[N:8]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 541667626,7-difluoro-3-styryl-1H-quinoxalin-2-one

Product 1

HCID 539868852-Chloro-6,7-difluoro-3-styrylquinoxalineYield 56%

Reagents, catalysts & solvents 1

HCID 142844-(Dimethylamino)pyridineCatalyst

Procedure

The above 6,7-difluoro-3-styryl-1H-quinoxalin-2-one (2.65 g, 0.93 mmol) was mixed with 4-dimethylaminopyridine (0.27 g) and POCl3 (27 ml) and the mixture was refluxed for 30 minutes. After cooling, the mixture was poured onto ice (400 ml) and the solid was filtered, washed with water (3×) and dried in vacuo overnight. Column chromatography on silica gel, eluting with ethyl acetate:heptane 1:20 afforded 1.6 g (56%) of the title compound.

Workup

  1. temperaturethe mixture was refluxed for 30 minutes
  2. temperatureAfter cooling
  3. additionthe mixture was poured onto ice (400 ml)
  4. filtrationthe solid was filtered
  5. washwashed with water (3×)
  6. customdried in vacuo overnight
  7. washColumn chromatography on silica gel, eluting with ethyl acetate:heptane 1:20

Sources & evidence

ORD record
ord-fb658b60d2e64e8e8a6ba7df66190762
Source dataset
uspto-grants-2005_08
Patent number
US06927214B1

Reaction notes

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