反应详情

To a solution of 4-bromo-2-chlorophenol (10 g, 48.2 mmol) in 25% aqueous ammonia solution (140 mL) was added a solution of potassium iodide (24 g, 144.6 mmol) and iodine (12.2 g, 48.2 mmol) in water (125 mL). The reaction mixture was stirred at ambient temperature for 4 h and quenched with 100 mL of water. The reaction was acidified by addition of concentrated HCl (150 mL) and extracted with ethyl acetate (3×40 mL). The combined organic extracts were dried over Na2SO4 and concentrated in vacuo to give the crude product which was purified by column chromatography (SiO2, 9:1 hexanes/ethyl acetate) providing 4-bromo-2-chloro-6-iodophenol (14 g, 89%) as an off-white solid: 1H NMR (CDCl3, 400 MHz) δ 7.74 (d, J=2.0 Hz, 1H), 7.47 (d, J=2.0 Hz, 1H), 5.93 (s, 1H).

1. customquenched with 100 mL of water
2. additionThe reaction was acidified by addition of concentrated HCl (150 mL)
3. extractionextracted with ethyl acetate (3×40 mL)
4. dry with materialThe combined organic extracts were dried over Na2SO4
5. concentrationconcentrated in vacuo
6. customto give the crude product which
7. customwas purified by column chromatography (SiO2, 9:1 hexanes/ethyl acetate)