Water → 2-Fluoroisonicotinic acid

HRID 1080683Notes

Reaction equation

HRID 1080683 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][N:3]=1.[Mn]([O-])(=O)(=O)=[O:10].[K+].[OH2:15]>>[F:1][C:2]1[CH:7]=[C:6]([C:8]([OH:10])=[O:15])[CH:5]=[CH:4][N:3]=1

Participants

4

Reactant 3

HCID 962WaterHCID 516875Potassium Permanganate2×HCID 27374032-Fluoro-4-methylpyridine

Product 1

HCID 3453602-Fluoroisonicotinic acid

Procedure

A stirred mixture of 30 grams of the above 2-fluoro-4-methylpyridine and potassium permanganate (100 g) in water (1.2 L) was heated at reflux. Additional potassium permanganate (50 g) was added after 1.5 hours and the stirred mixture was maintained at reflux for 15 hours. The reaction mixture was then steam distilled to remove unreacted starting material, the hot residual aqueous solution was filtered, and the filtrate was concentrated in vacuo to 450 mL. The solution was cooled on an ice-bath and acidified with concentrated HCl to pH 2.0. The resulting precipitate was collected and crystallized from water and gave 13.56 g of 2-fluoropyridine-4-carboxylic acid having a melting point of 220°-224° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux
  3. temperaturethe stirred mixture was maintained
  4. temperatureat reflux for 15 hours
  5. distillationsteam distilled
  6. customto remove unreacted
  7. filtrationthe hot residual aqueous solution was filtered
  8. concentrationthe filtrate was concentrated in vacuo to 450 mL
  9. temperatureThe solution was cooled on an ice-bath
  10. customThe resulting precipitate was collected
  11. customcrystallized from water

Sources & evidence

ORD record
ord-f76a0af459b54cc38824d635b7a2ecb1
Source dataset
uspto-grants-1996_12
Patent number
US05583148

Reaction notes

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