Methyl 2,5-dihydroxybenzoate

67-56-1

490-79-9

2150-46-1

2,5-Dihydroxybenzoic acid (5.00 g, 32.5 mmol) was dissolved in methanol (33 mL) and concentrated sulfuric acid (5 mL) was added slowly and dropwise. The reaction mixture was heated under reflux conditions for 16 hours. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was removed under vacuum. The residue was neutralized with saturated aqueous NaHCO3 to pH 7. Subsequently, the product was extracted with ethyl acetate (50 mL x 3), the organic layers were combined, washed with brine (20 mL), dried over anhydrous MgSO4, filtered and the filtrate was evaporated to give the light brown powdery product methyl 2,5-dihydroxybenzoate (5.13 g, 94% yield). The structure of the product was analyzed by 1H NMR (CDCl3) δ 10.35 (s,1H), 7.29 (d, J = 3.2 Hz, 1H), 7.02 (dd, J = 8.7,3.2 Hz, 1H), 6.89 (d, J = 8.7 Hz, 1H), 4.69 (s,1H), 3.95 (s,1H); 13C NMR (CDCl3) δ 170.1,155.8,147.6,124.0,118.5,114.7,112.1,52.4; HRMS (ESI):[M-H]- Calculated value of C8H7O4 167.0344, confirmed by measured value of 167.0359.