Sodium Hydroxide → 4-Bromo-3-fluorobenzoic acid

HRID 341739Notes

Reaction equation

HRID 341739 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 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 silica. The silica was washed with boiling water, followed by ethyl acetate. The cooled aqueous layer was acidified to pH1 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 (b.p. 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 silica
  5. washThe silica 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 (b.p. 60°-80° C.)

Sources & evidence

ORD record
ord-3cff83f3776c40d7970dca9f4116ab98
Source dataset
uspto-grants-1999_01
Patent number
US05856274

Reaction notes

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