Methanol → Methyl 2,3-dihydroxy-4-methoxybenzoate

HRID 2196100Notes

Reaction equation

HRID 2196100 reaction equation
[OH:1][C:2]1[C:10]([OH:11])=[C:9]([O:12][CH3:13])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].OS(O)(=O)=O.[CH3:19]O>>[OH:1][C:2]1[C:10]([OH:11])=[C:9]([O:12][CH3:13])[CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:19])=[O:5]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 775342,3-Dihydroxy-4-methoxybenzoic acid

Product 1

HCID 11694090Methyl 2,3-dihydroxy-4-methoxybenzoate

Procedure

A solution of commercially available 2,3-dihydroxy-4-methoxybenzoic acid (11.6 g, 63 mmol) in anhydrous MeOH (150 mL) was cooled in an ice-bath and conc. H2SO4 (8 mL) added dropwise. The reaction mixture was refluxed for 12 h, then cooled to rt and the solvent was removed under reduced pressure. H2O (100 mL) and sat aq NaHCO3 (50 mL) were added and extracted with EtOAc (3×100 mL). The combined organic phase was dried (Na2SO4), filtered and concentrated in vacuo to afford compound 513 as a pale yellow solid, which was used in the next step without further purification. LC-MS: RT=2.31 min.; m/z 197.3 (M−H)−. 1H NMR (CDCl3): δ 10.83 (1H, s), 7.41 (1H, d, J 9.0), 6.50 (1H, d, J 8.9), 5.45 (1H, s), 3.94 (3H, s), 3.93 (3H, s).

Workup

  1. temperatureThe reaction mixture was refluxed for 12 h
  2. customthe solvent was removed under reduced pressure
  3. additionwere added
  4. extractionextracted with EtOAc (3×100 mL)
  5. dry with materialThe combined organic phase was dried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-74863f19b62c4e0793bc0b33bc70cccd
Source dataset
uspto-grants-2012_12
Patent number
US08338431B2

Reaction notes

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