Sodium Hydroxide → 2-Fluoro-4-methoxybenzoic acid

HRID 501819Notes

Reaction equation

HRID 501819 reaction equation
[OH-:1].[Na+].BrBr.[F:5][C:6]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[CH:8][C:7]=1[C:14](=[O:16])C>O.O1CCOCC1>[F:5][C:6]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[CH:8][C:7]=1[C:14]([OH:16])=[O:1]

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 24408BromineHCID 5928212'-Fluoro-4'-methoxyacetophenone

Product 1

HCID 27745422-Fluoro-4-methoxybenzoic acidYield 82.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 312751,4-DioxaneSolvent

Procedure

23.30 g of sodium hydroxide was dissolved in 118 mL of water and was ice-cooled, to which 9.23 mL of bromine was added dropwise over 20 minutes and then a solution of 9.80 g of 1-(2-fluoro-4-methoxyphenyl)-1-ethanone in 88 mL of 1,4-dioxane was added dropwise over one hour at −10° C. The resultant reaction mixture was cooled to room temperature, to which water was added, and then an aqueous phase was separated therefrom. A solution of 7.23 g of sodium thiosulfate in 100 mL of water was added to the aqueous phase, and then 12M hydrochloric acid was further added until the pH value of this aqueous phase reached 2. The resultant precipitate was filtered therefrom and washed with water to yield 8.20 g of 2-fluoro-4-methoxybenzoic acid as white solid.

Workup

  1. additionwas added dropwise over 20 minutes
  2. customThe resultant reaction mixture
  3. additionwas added
  4. customan aqueous phase was separated
  5. additionA solution of 7.23 g of sodium thiosulfate in 100 mL of water was added to the aqueous phase
  6. addition12M hydrochloric acid was further added until the pH value of this aqueous phase
  7. filtrationThe resultant precipitate was filtered
  8. washwashed with water

Sources & evidence

ORD record
ord-439a5ed4ced049fcab533d528887d521
Source dataset
uspto-grants-2010_08
Patent number
US07772285B2

Reaction notes

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