Methyl 3-methoxy-4-methylbenzoate

586-30-1

77-78-1

3556-83-0

Synthesis of methyl 3-methoxy-4-methylbenzoate: 3-hydroxy-4-methylbenzoic acid (15.2 g, 100 mmol) was suspended in 30 mL of water, and the pH was adjusted to 11.5 with 50% aqueous sodium hydroxide. dimethyl sulfate (15.8 mL, 167 mmol) was added slowly and dropwise over a period of 4 h at about 20 °C, while maintaining the pH of the reaction system between 11.2 and 11.8 by supplementing with sodium hydroxide solution. pH of the reaction system between 11.2 and 11.8. Subsequently, the reaction mixture was warmed up to 55 °C and the addition of dimethyl sulfate (6 mL, 63 mmol) was continued dropwise over a period of 4 hours while controlling the pH in the range of 8.2 to 9.0. Upon completion of the reaction, the organic phase was separated and purified by silica gel fast column chromatography (eluent: petroleum ether/ethyl acetate = 10/1, v/v) to afford the target product methyl 3-methoxy-4-methylbenzoate (11.8 g, 66% yield). The product was confirmed by 1H NMR (300 MHz, CDCl3): δ 7.55 (d, 2H, J=7.5 Hz), 7.48 (s, 1H), 7.18 (d, 1H, J=7.5 Hz), 3.91 (s, 3H), 3.89 (s, 3H), 2.26 (s, 3H); the LC-MS analysis showed m/z=181 (MH)+.