反应详情

Nitric acid (68-70%, 125 mL) was slowly mixed with glacial acetic acid (125 ml) at room temperature, followed by addition of NaNO2 (400 mg, 5.8 mmol) and 3-iodoanisole (10 g, 42.7 mmol). After the reaction was stirred at room temperature for 24 hours, I2 (10.8 g, 42.7 mmol) was added and the mixture was stirred at 60° C. overnight. The reaction mixture was poured into ice-water (500 ml) and extracted by CH2Cl2 (100 ml) three times. The combined organic phase was neutralized with saturated NaHCO3 solution (500 ml), washed with aqueous solution of Na2S2O3 (20%, 100 ml), dried over Na2SO4, and concentrated in vacuo. The residue was purified by silica gel column chromatography to yield crude 3,6-diiodo-4-nitroanisole (5.4 g), which is mixed with one unknown by-product (20%) and used in the next step without further purification. 1H NMR (400 MHz, CDCl3): δ 8.42 (s, 1H, Ph-H), 7.33 (s, 1H, Ph-H), 3.97 (s, 3H, OCH3).

1. stirringthe mixture was stirred at 60° C. overnight
2. extractionextracted by CH2Cl2 (100 ml) three times
3. washwashed with aqueous solution of Na2S2O3 (20%, 100 ml)
4. dry with materialdried over Na2SO4
5. concentrationconcentrated in vacuo
6. customThe residue was purified by silica gel column chromatography