Hydrochloric Acid → 2-Methoxy-4-methylbenzoic acid

HRID 1881796Notes

Reaction equation

HRID 1881796 reaction equation
[OH:1][C:2]1[CH:10]=[C:9]([CH3:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:12]([O-])([O-])=O.[K+].[K+].[OH-].[K+].Cl>CC(C)=O.CO.CI>[CH3:12][O:1][C:2]1[CH:10]=[C:9]([CH3:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 57882-Hydroxy-p-toluic acidHCID 11430Potassium CarbonateHCID 14797Potassium Hydroxide

Product 1

HCID 5971642-Methoxy-4-methylbenzoic acidYield 24,462.6%

Reagents, catalysts & solvents 3

HCID 6328Methyl iodideCatalystHCID 180AcetoneSolventHCID 887MethanolSolvent

Procedure

To a solution of 2-hydroxy-4-methylbenzoic acid (25 g, 0.164 mol) in acetone (350 mL) was added K2CO3 (68 g, 0.492 mmol) followed by MeI (41 mL, 0.656 mmol) and the reaction mixture heated at reflux for 48 hrs. After cooling to r.t. the reaction mixture was filtered and the filtrate was evaporated to give the crude methyl 2-methoxy-4-methylbenzoate. KOH (11.3 g, 1.2 eq) was dissolved in MeOH (300 mL) and the crude ester was added to the mixture and the solution heated at reflux 48 hrs. After cooling the reaction mixture was acidified with aq. HCl (1N) and extracted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4, filtered and evaporated. The residue was triturated with Ethyl acetate/Hexane to give 20 g of 2-methoxy-4-methylbenzoic acid as a cream white solid (85% yield)

Workup

  1. temperaturethe reaction mixture heated
  2. temperatureat reflux for 48 hrs
  3. filtrationwas filtered
  4. customthe filtrate was evaporated
  5. customto give the crude methyl 2-methoxy-4-methylbenzoate
  6. temperaturethe solution heated
  7. temperatureat reflux 48 hrs
  8. temperatureAfter cooling the reaction mixture
  9. extractionextracted with ethyl acetate
  10. washThe organic layer was washed with brine
  11. dry with materialdried over MgSO4
  12. filtrationfiltered
  13. customevaporated
  14. customThe residue was triturated with Ethyl acetate/Hexane

Sources & evidence

ORD record
ord-e23ccd826c9f48e19f6b63a957f0b187
Source dataset
uspto-grants-2012_11
Patent number
US08318947B2

Reaction notes

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