Synthesis

2-Bromo-5-fluorophenol (1 g, 5.2 mmol), deuterated methyl iodide (911 mg, 6.3 mmol), and potassium carbonate (1.45 g, 10.5 mmol) were added to N, N-dimethylformamide (10 mL). The reaction solution was stirred and reacted for 6 h. After that, the reaction solution was cooled to room temperature. Ethyl acetate (20 mL) was added, and the reaction solution was washed with water (20 mL×3). The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography with eluent system A to obtain 1-bromo-4-fluoro-2-(methoxy-d3)benzene.