General procedure for the synthesis of 2-fluoro-4-iodophenol from 2-fluorophenol: Iodine (1.06 g, 4.18 mmol) was added in a single addition to a stirring solution of 2-fluorophenol (0.47 g, 4.18 mmol) in concentrated ammonia (22 ml) at room temperature. The reaction mixture was stirred overnight at room temperature and the solvent was removed by evaporation under reduced pressure. The residue was partitioned between ethyl acetate (100 ml) and water (40 ml). The organic phase was washed sequentially with 5% sodium bisulfite solution and brine (10 ml), dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated to dryness under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane/ethyl acetate, 9:1) to afford 2-fluoro-4-iodophenol (0.42 g, 42% yield) as a colorless solid.1H-NMR (CDCl3) δ 7.3-7.4 (m, 2H), 6.75 (t, J=8.8 Hz, 1H), 5.17 (s, 1H).
