Reaktion #74169

Reaktionsgleichung

4-bromo-3-(2,6-difluoro-3-nitrophenyl)-1-methyl-1H-pyrazole

4-bromo-5-(2,6-difluoro-3-nitrophenyl)-1-methyl-1H-pyrazole

ammonium chloride

→

3-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2,4-difluoroaniline

Lösungsmittel

dioxane

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwere refluxed
2. 2
   TemperaturAfter cooling
3. 3
   Filtrationthe mixture was filtered
4. 4
   Einengenthe filtrate was concentrated
5. 5
   Waschenwashed with saturated aqueous solution of sodium hydrogen carbonate and water
6. 6
   Trocknendried over anhydrous sodium sulfate
7. 7
   Einengenconcentrated
8. 8
   workup.ADDITIONThe crude mixture of 3-(4-bromo-1-methyl-1H-pyrazol-3-yl)-2,4-difluoroaniline

Vorschrift

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%).

Quelle