Sulfuric Acid → Methyl 2,4-Dihydroxybenzoate

HRID 2121206Notes

Reaction equation

HRID 2121206 reaction equation
[OH:1][C:2]1[CH:10]=[C:9]([OH:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.[CH:17](OC)(OC)OC>CO.O>[CH3:17][O:5][C:4](=[O:6])[C:3]1[CH:7]=[CH:8][C:9]([OH:11])=[CH:10][C:2]=1[OH:1]

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 14912,4-Dihydroxybenzoic AcidHCID 9005Trimethyl orthoformate

Product 1

HCID 16523Methyl 2,4-DihydroxybenzoateYield 79.7%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution in methanol (50 mL) of 2,4-dihydroxybenzoic acid (1.54 g, 10 mmol) was added sulfuric acid (0.5 mL) and trimethyl orthoformate (1.6 mL, 15 mmol) and the reaction mixture was stirred at reflux for 36 hours. The reaction mixture was cooled to ambient temperature and diluted with water. The methanol was evaporated in vacuo. The residue was diluted with water and extracted with ether (3×). The combined ether extracts were washed with saturated aqueous sodium bicarbonate (2×) and brine, dried, filtered and concentrated in vacuo to give 2,4-dihydroxybenzoic acid methyl ester (1.34 g) as a white solid.

Workup

  1. temperatureat reflux for 36 hours
  2. customThe methanol was evaporated in vacuo
  3. additionThe residue was diluted with water
  4. extractionextracted with ether (3×)
  5. washThe combined ether extracts were washed with saturated aqueous sodium bicarbonate (2×) and brine
  6. customdried
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d6e344ceddb14c9d8d94769a9c623ea6
Source dataset
uspto-grants-2004_02
Patent number
US06693123B2

Reaction notes

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