Sodium Hydroxide → 4-Bromo-3-fluorobenzoic acid

HRID 1741808Notes

Reaction equation

HRID 1741808 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][C:3]=1[F:9].[OH-:10].[Na+].[Mn]([O-])(=O)(=O)=[O:13].[K+]>N1C=CC=CC=1.O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([OH:13])=[O:10])=[CH:4][C:3]=1[F:9]

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 516875Potassium PermanganateHCID 5732804-Bromo-3-fluorotoluene

Product 1

HCID 27733414-Bromo-3-fluorobenzoic acidYield 52.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1049PyridineSolvent

Procedure

A solution of 4-bromo-3-fluorotoluene (35 g) and sodium hydroxide (7.7 g) in pyridine and water was mechanically stirred and heated to reflux. Potassium permanganate (123 g) was added to the mixture over 2 hours. The resulting suspension was heated at reflux for a further 3 hours. The mixture was filtered hot through hyflo. The hyflo was washed with boiling water, followed by ethyl acetate. The cooled aqueous layer was acidified to pH 1 with concentrated hydrochloric acid and extracted with ethyl acetate. The organic extract was washed with water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue triturated with petroleum spirit (bp 60°-80° C.) to give 4-bromo-3-fluorobenzoic acid as a white solid (21.25 g), m.p. 213°-215° C.

Workup

  1. temperatureheated to reflux
  2. temperatureThe resulting suspension was heated
  3. temperatureat reflux for a further 3 hours
  4. filtrationThe mixture was filtered hot through hyflo
  5. washThe hyflo was washed with boiling water
  6. extractionextracted with ethyl acetate
  7. extractionThe organic extract
  8. washwas washed with water
  9. dry with materialdried (MgSO4)
  10. filtrationfiltered
  11. customThe filtrate was evaporated to dryness
  12. customthe residue triturated with petroleum spirit (bp 60°-80° C.)

Sources & evidence

ORD record
ord-35aff114535e4e4a8aef68838c68aedc
Source dataset
uspto-grants-1994_08
Patent number
US05334753

Reaction notes

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