A) General procedure for synthesizing 2-chloro-3-methoxyphenol: 2-chloro-1,3-benzenediol (22.8 g) was added to an aqueous solution (100 mL) of potassium hydroxide (11.0 g). Subsequently, dimethyl sulfate (19.9 g) was slowly added while maintaining the temperature of the reaction mixture at 10 °C to 20 °C. The reaction mixture was stirred at 100 °C for 2 days. After completion of the reaction, the reaction mixture was acidified with 2N hydrochloric acid and extracted with dichloromethane. The organic layer was dried with anhydrous sodium sulfate and evaporated under reduced pressure to remove the solvent. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/petroleum ether) to afford the target product 2-chloro-3-methoxyphenol (18.0 g). The product was characterized by 1H NMR (400 MHz, DMSO-d6) with chemical shifts of δ 3.78 (3H, s), 6.54-6.58 (2H, m), 7.05 (1H, t, J = 8.4 Hz), 10.04 (1H, brs).
