Methanol → Benzoic acid, 2-hydroxy-3-methyl-, methyl ester

HRID 1814787Notes

Reaction equation

HRID 1814787 reaction equation
[OH:1][C:2]1[C:10]([CH3:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.[CH3:17]O>>[OH:1][C:2]1[C:10]([CH3:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:17])=[O:5]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric Acid2×HCID 67383-Methylsalicylic Acid

Product 1

HCID 31835Benzoic acid, 2-hydroxy-3-methyl-, methyl ester

Conditions

Temperature
70 °C

Procedure

To a solution of 2-hydroxy-3-methylbenzoic acid (18.1 g, 119 mmol) in 70 mL of methanol is added dropwise 3.3 mL of concentrated sulfuric acid. The resulting solution is heated under reflux for 24 hours. Another 7 mL of concentrated sulfuric acid is added and the reaction is heated at 70° C. overnight. The mixture is cooled and a pink layer separated. This layer is dissolved in 200 mL of ethyl acetate and the solution is washed with saturated aqueous sodium bicarbonate and brine, dried over sodium sulfate, filtered and concentrated to give an oil which is purified by chromatography on silica gel using a mixture of 30% ethyl acetate and 70% hexane as the eluent. Methyl 2-hydroxy-3-methylbenzoate is obtained as a clear oil.

Workup

  1. temperatureThe resulting solution is heated
  2. temperatureunder reflux for 24 hours
  3. temperatureThe mixture is cooled
  4. customa pink layer separated
  5. dissolutionThis layer is dissolved in 200 mL of ethyl acetate
  6. washthe solution is washed with saturated aqueous sodium bicarbonate and brine
  7. dry with materialdried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customto give an oil which
  11. customis purified by chromatography on silica gel using
  12. additiona mixture of 30% ethyl acetate and 70% hexane as the eluent

Sources & evidence

ORD record
ord-98626af3989048c3aebb8054c5f6a8c7
Source dataset
uspto-grants-2005_04
Patent number
US06878707B2

Reaction notes

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