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General procedure for the synthesis of (4-bromo-3-methylisoxazol-5-yl)methyl acetate from 3-methyl-5-isoxazolemethanol acetate: To a solution of (3-methylisoxazol-5-yl)methyl acetate (0.979 g, 6.31 mmol) in acetic acid (10 mL, 175 mmol) was added sequentially N-bromosuccinimide (1.30 g, 7.30 mmol) and sulfuric acid (0.65 mL, 12.19 mmol). The reaction mixture was heated to 110 °C and maintained for 1 hour. Upon completion of the reaction, the mixture was cooled to room temperature and slowly poured into a beaker containing ice and saturated sodium bicarbonate solution. The two-phase mixture was vigorously stirred and the basic aqueous phase (pH 8-9) was subsequently extracted with ethyl acetate (2 x 15 mL). The organic phase was washed sequentially with 2% sodium thiosulfate solution and brine (20 mL), dried over anhydrous sodium sulfate and concentrated to give a light yellow oil. The crude product was purified by a Biotage purification system (isocratic elution, 10% ethyl acetate: 90% hexane) to afford the title compound (4-bromo-3-methylisoxazol-5-yl)methyl acetate (1.30 g, 5.55 mmol, 88% yield) as a colorless to light yellow oil. lc/ms m/z 234 [M + H]+.

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