反应详情

To 4-chloro-3-(4-chloro-2-fluoro-5-nitrophenyl)-5-difluoromethoxy-1-methyl-1H-pyrazole (3.0 g, 8.5 mmoles) in a mixture of 15 ml ethanol and 15 ml conc. hydrochloric acid was added stannous chloride (7.70 g, 34 mmole) and the reduction was conducted under reflux for 8 hours. Then the product solution was poured into ice-cold water, the resulting mixture was made alkaline with 20% aqueous NaOH, and the objective product was extracted with ethyl acetate. Dehydration and concentration of the extract solution and purification of the residue by column chromatography gave the title compound (2.15 g), yield 78%.

1. temperatureunder reflux for 8 hours
2. additionThen the product solution was poured into ice-cold water
3. extractionthe objective product was extracted with ethyl acetate
4. customDehydration and concentration of the extract solution and purification of the residue by column chromatography