反应详情

Mix 4-fluoro-2-bromo-6-nitroaniline (15.5 g, 66.0 mmol) and 50% sulfuric acid (200 mL) and cool to 0°-5° C. Add, by dropwise addition, a solution of sodium nitrite (6.0 g, 86.4 mmol) in water (50 mL). Stir for 30 minutes and add solid potassium iodide (29 g, 173 mmol). Take up the product in ethyl acetate (300 mL), wash with saturated sodium hydrogen carbonate (2×200 mL), saturated sodium metabisulfite (2×200 mL) and water (200 mL). Dry (MgSO4), evaporate the solvent in vacuo and purify by silica gel chromatography to give 1-iodo-2-nitro-4-fluoro-6-bromobenzene as a yellow crystalline solid (17.81 g, 76%); mp 75°-76° C.

1. temperaturecool to 0°-5° C
2. additionAdd, by dropwise addition
3. washwash with saturated sodium hydrogen carbonate (2×200 mL), saturated sodium metabisulfite (2×200 mL) and water (200 mL)
4. dry with materialDry (MgSO4)
5. customevaporate the solvent in vacuo
6. custompurify by silica gel chromatography