General procedure for the synthesis of methyl 3-methoxy-5-methylbenzoate from methyl 3-hydroxy-5-methylbenzoate and iodomethane: To a solution of methyl 3-hydroxy-5-methylbenzoate (20.0 g, 120 mmol) in N,N-dimethylformamide (120 mL) was added sequentially iodomethane (11.2 mL, 180 mmol), cesium carbonate (4.65 g, 180 mmol) and catalytic amount of 4-dimethylaminopyridine. 180 mmol) and a catalytic amount of 4-dimethylaminopyridine. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, it was diluted with water (200 mL) and extracted with ethyl acetate (3 x 150 mL). The organic phases were combined, washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and concentrated to afford the target product methyl 3-methoxy-5-methylbenzoate (19.9 g, 92% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 2.38 (s, 3H), 3.84 (s, 3H), 3.91 (s, 3H), 6.93 (s, 1H), 7.37 (s, 1H), 7.48 (s, 1H).
