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

Participants

Reaction Steps

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).

Provenance & Evidence