Sulfuric Acid → Methyl 3-hydroxy-2-methylbenzoate

HRID 906122Notes

Reaction equation

HRID 906122 reaction equation
[OH:1][C:2]1[C:3]([CH3:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6].S(=O)(=O)(O)O.[C:17](=O)(O)[O-].[Na+]>CO>[OH:1][C:2]1[C:3]([CH3:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([O:7][CH3:17])=[O:6]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 2520233-Hydroxy-2-methylbenzoic AcidHCID 516892Sodium Bicarbonate

Product 1

HCID 12488879Methyl 3-hydroxy-2-methylbenzoateYield 97%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 3-hydroxy-2-methylbenzoic acid (5 g, 33 mmol) and concentrated sulfuric acid (3 mL) in methanol (300 mL) was stirred at reflux for 48 hours. The mixture was cooled to room temperature and the pH was adjusted to 7 using solid sodium bicarbonate. Some methanol was evaporated and residue was partitioned between saturated aqueous sodium bicarbonate and ethyl acetate. The organic portion was washed with brine then dried over anhydrous sodium sulfate. Filtration and concentration afforded 5.3 g, 32 mmol (97%) of methyl 3-hydroxy-2-methylbenzoate. 1H NMR (400 MHz, CDCl3): 7.41 (d, 1H), 7.13-7.09 (m, 1H), 6.94 (d, 1H), 3.89 (s, 3H), 2.46 (s, 3H). MS (EI) for C9H10O3: 167 (MH+).

Workup

  1. temperatureat reflux for 48 hours
  2. customSome methanol was evaporated
  3. customresidue was partitioned between saturated aqueous sodium bicarbonate and ethyl acetate
  4. washThe organic portion was washed with brine
  5. dry with materialthen dried over anhydrous sodium sulfate
  6. filtrationFiltration and concentration

Sources & evidence

ORD record
ord-82a7b0f281bb4cb3bba9c95546f9264f
Source dataset
uspto-grants-2011_09
Patent number
US08012956B2

Reaction notes

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