Protocatechuic Acid → Methyl 3,4-Dihydroxybenzoate

Participants

Reaction Steps

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).

Provenance & Evidence