4-Bromo-2-chlorobenzoic acid methyl ester

59748-90-2

185312-82-7

A. Methyl esterification: Dry hydrogen chloride gas was passed into a 100 ml methanol solution containing 10 g (42.5 mmol) of 4-bromo-2-chlorobenzoic acid until the solution began to reflux. The reaction mixture was stirred at room temperature overnight. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming that the reaction was essentially complete, the reaction mixture was concentrated under reduced pressure to give the crude product. The crude product was redissolved in ether and washed sequentially with deionized water (twice) and saturated sodium chloride solution. The organic phase was dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to afford 10 g of the light tan oily target product methyl 2-chloro-4-bromobenzoate in 94% yield.