反应详情

A mixture of 4-bromo-3-(2,6-difluoro-3-nitrophenyl)-1-methyl-1H-pyrazole and its regioisomer 4-bromo-5-(2,6-difluoro-3-nitrophenyl)-1-methyl-1H-pyrazole (0.35 g, 1.1 mmol), powdered zinc (0.39 g, 6 mmol) and ammonium chloride (0.6 g, 11 mmol) in dioxane (6 mL) and water (2 mL) were refluxed under good stirring for 3 h. After cooling, the mixture was filtered and the filtrate was concentrated. The residue was taken up with dichloromethane, washed with saturated aqueous solution of sodium hydrogen carbonate and water, dried over anhydrous sodium sulfate and concentrated. The crude mixture of 3-(4-bromo-1-methyl-1H-pyrazol-3-yl)-2,4-difluoroaniline and its regioisomer 3-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2,4-difluoroaniline was obtained as a brownish solid (0.33 g, 95%).

1. temperaturewere refluxed
2. temperatureAfter cooling
3. filtrationthe mixture was filtered
4. concentrationthe filtrate was concentrated
5. washwashed with saturated aqueous solution of sodium hydrogen carbonate and water
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated
8. additionThe crude mixture of 3-(4-bromo-1-methyl-1H-pyrazol-3-yl)-2,4-difluoroaniline