反应详情

温度

-5 °C

Methyl 4-amino-2,6-dichlorobenzoate (104 g, 0.14 mol) was added to concentrated hydrochloric acid (884 mL) and the mixture was cooled (−5° C.). A solution of sodium nitrite (55.2 g, 0.8 mol) in water (312 mL) was added dropwise with vigorous stirring, maintaining the reaction temperature in a range of −5° C. and 0° C. After 30 min, the mixture was filtered and the filtrate was added to a cooled (0° C.) and mechanically stirred solution of potassium iodide (352.3 g, 2.12 mol) in water (200 mL). The mixture was warmed to room temperature and stirred overnight. The reaction was diluted with ethyl acetate (1 L) and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (1 L). The combined organic extracts were washed with saturated solution of NaHSO3, dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (petroleum ether/EtOAc 50/1) to give methyl 2,6-dichloro-4-iodobenzoate (140 g, yield 90%) as a yellow oil. 1H NMR (CDCl3 400 MHz) δ 7.70 (s, 2H), 3.97 (s, 3H).

1. temperaturemaintaining the reaction temperature in a range of −5° C. and 0° C
2. filtrationthe mixture was filtered
3. additionthe filtrate was added to
4. temperatureThe mixture was warmed to room temperature
5. customthe organic phase was separated
6. extractionThe aqueous phase was extracted with ethyl acetate (1 L)
7. washThe combined organic extracts were washed with saturated solution of NaHSO3
8. dry with materialdried over Na2SO4
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by column chromatography on silica gel (petroleum ether/EtOAc 50/1)