Methyl 2-chloro-6-methylbenzoate (1 g, 5.4 mmol) was used as starting material and dissolved in carbon tetrachloride (50 mL). Subsequently, N-bromosuccinimide (1 g, 5.9 mmol) and benzoyl peroxide (0.131 g, 0.5 mmol) were sequentially added to this solution. The reaction mixture was stirred continuously at 80 °C for 10 hours. After completion of the reaction, the mixture was filtered through diatomaceous earth to remove insoluble impurities. The filtrate was concentrated under reduced pressure to afford the target product methyl 2-(bromomethyl)-6-chlorobenzoate (1.2 g). The structure of the product was confirmed by LC-MS with a calculated exact mass of 261.94 and a measured value of m/z 263.0 [M + H]+.
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