Phosphorus oxychloride → 5-Chloro-2-(3-fluoropyridin-4-yl)-3-pyridin-3-ylpyrazine

HRID 1710690Notes

Reaction equation

HRID 1710690 reaction equation
[F:1][C:2]1[CH:3]=[N:4][CH:5]=[CH:6][C:7]=1[C:8]1[N:9]=[CH:10][C:11](=O)[NH:12][C:13]=1[C:14]1[CH:15]=[N:16][CH:17]=[CH:18][CH:19]=1.P(Cl)(Cl)([Cl:23])=O>>[Cl:23][C:11]1[N:12]=[C:13]([C:14]2[CH:15]=[N:16][CH:17]=[CH:18][CH:19]=2)[C:8]([C:7]2[CH:6]=[CH:5][N:4]=[CH:3][C:2]=2[F:1])=[N:9][CH:10]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 594575875-(3-Fluoropyridin-4-yl)-6-pyridin-3-ylpyrazin-2(1H)-one

Product 1

HCID 594576235-Chloro-2-(3-fluoropyridin-4-yl)-3-pyridin-3-ylpyrazineYield 33%

Procedure

A suspension of 5-(3-fluoropyridin-4-yl)-6-pyridin-3-ylpyrazin-2(1H)-one (0.79 g, 2.95 mmol) in phosphorus oxychloride (5 mL) was heated to reflux and stirred overnight. The mixture was evaporated and carefully neutralised with 4% aqueous sodium hydrogen carbonate solution with external cooling. The mixture was extracted with ethyl acetate and the organic layer was washed with brine, dried (MgSO4) and evaporated. The residue was purified by silica gel chromatography (CH2Cl2 to CH2Cl2/MeOH 98:2) to give the title compound (0.279 g, 33%) as an off-white solid.

Workup

  1. temperaturewas heated
  2. temperatureto reflux
  3. customThe mixture was evaporated
  4. extractionThe mixture was extracted with ethyl acetate
  5. washthe organic layer was washed with brine
  6. dry with materialdried (MgSO4)
  7. customevaporated
  8. customThe residue was purified by silica gel chromatography (CH2Cl2 to CH2Cl2/MeOH 98:2)

Sources & evidence

ORD record
ord-d19471de7c5a43da8be4af50b27d8a12
Source dataset
uspto-grants-2010_09
Patent number
US07790728B2

Reaction notes

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