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A) Synthesis of 5-bromo-2-hydroxy-4-methylbenzoic acid: 2-hydroxy-4-methylbenzoic acid (5.00 g) was dissolved in acetic acid (70.0 mL) and bromine (1.68 mL) was added slowly and dropwise. The reaction mixture was stirred at room temperature for 5.5 hours. Upon completion of the reaction, water was added to the mixture and the precipitate was collected by filtration. The precipitate was dried under reduced pressure to give the target compound 5-bromo-2-hydroxy-4-methylbenzoic acid (6.78 g). The result of mass spectrometry analysis: [M-H]? 229.0.

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