Acetic Anhydride → 4-Acetoxy-3-methylbenzoic acid

HRID 1003358Notes

Reaction equation

HRID 1003358 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11].[C:12](OC(=O)C)(=[O:14])[CH3:13]>N1C=CC=CC=1>[C:12]([O:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11])(=[O:14])[CH3:13]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 681384-Hydroxy-3-methylbenzoic acid

Product 1

HCID 187970704-Acetoxy-3-methylbenzoic acidYield 52.7%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 5.42 g (35.6 mmol) of the 4-hydroxy-3-methylbenzoic acid in 50 ml of pyridine was added to 16.8 ml (178 mmol) of acetic anhydride. The resulting mixture was stirred overnight at room temperature, and the reaction mixture was distilled off under reduced pressure. The residue was dissolved in ethyl acetate. The resulting solution was washed with 2N hydrochloric acid and a saturated aqueous solution of sodium chloride and was then dried over Na2SO4. The solvent was distilled off under reduced pressure. The residue was recrystallized from ethyl acetate-hexane, whereby 3.64 g of 4-acetoxy-3-methylbenzoic acid were obtained as white powder (yield: 52.6%).

Workup

  1. distillationthe reaction mixture was distilled off under reduced pressure
  2. dissolutionThe residue was dissolved in ethyl acetate
  3. washThe resulting solution was washed with 2N hydrochloric acid
  4. dry with materiala saturated aqueous solution of sodium chloride and was then dried over Na2SO4
  5. distillationThe solvent was distilled off under reduced pressure
  6. customThe residue was recrystallized from ethyl acetate-hexane

Sources & evidence

ORD record
ord-adc52fe9d5864397bda2a39796a34197
Source dataset
uspto-grants-2000_04
Patent number
US06046212

Reaction notes

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