General procedure for the synthesis of methyl 4-bromomethyl-2-methoxybenzoate from methyl 2-methoxy-4-methylbenzoate: over a period of 1.5 h, bromine (6.19 mL, 120 mmol) was slowly added dropwise over a period of 1.5 h to a reflux mixture of methyl 2-methoxy-4-methylbenzoate (21.625 g, 120 mmol) in carbon tetrachloride (240 mL) dissolved in a carbon tetrachloride (75 mL). During the dropwise addition, the reaction mixture was irradiated using a 250W tungsten lamp. After dropwise addition, the reaction was continued at reflux for 15 minutes. Upon completion of the reaction, the mixture was concentrated and the solvent was removed under vacuum to afford methyl 4-bromomethyl-2-methoxybenzoate as an oily product (29.864 g, 96% yield). The product was confirmed by NMR hydrogen spectrum (400 MHz, CDCl3): δ 2.40 (s, 3H), 3.87 (s, 3H), 3.91 (s, 3H), 4.44 (s, 2H). Mass spectrometry (FIA-MS) showed the molecular ion peak m/e: 259 ([M+1]+).
