Protocatechuic Acid → Methyl 3,4-Dihydroxybenzoate

HRID 1908955Notes

Reaction equation

HRID 1908955 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[OH:11])[C:5]([OH:7])=[O:6].[CH3:12]O>>[CH3:12][O:6][C:5](=[O:7])[C:4]1[CH:8]=[CH:9][C:10]([OH:11])=[C:2]([OH:1])[CH:3]=1

Participants

3

Reactant 2

HCID 72Protocatechuic AcidHCID 887Methanol

Product 1

HCID 287064Methyl 3,4-DihydroxybenzoateYield 96%

Procedure

A solution of 3,4-dihydroxybenzoic acid (5.0 g, 32 mmol) in methanol (80 mL) containing c-H2SO4 (3 mL) was heated at reflux for 4 hrs and cooled to room temperature. After concentrating under reduced pressure, the residue was dissolved in ethyl acetate and washed successively with water, saturated NaHCO3, and brine. The organic fraction was dried over MgSO4 and concentrated to give 3,4-dihydroxybenzoic acid methyl ester (5.2 g, 96%). 1H NMR (DMSO-d6, 600 MHz) δ 9.77 (s, 1H), 9.35 (s, 1H), 7.35 (s, 1H), 7.30 (d, 1H, J=7.8 Hz), 6.79 (d, 1H, J=7.8 Hz), 3.78 (s, 3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 4 hrs
  3. concentrationAfter concentrating under reduced pressure
  4. dissolutionthe residue was dissolved in ethyl acetate
  5. washwashed successively with water, saturated NaHCO3, and brine
  6. dry with materialThe organic fraction was dried over MgSO4
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-a93a7dcfdebe46c1aaa0dd6665158d53
Source dataset
uspto-grants-2013_12
Patent number
US08598342B2

Reaction notes

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