반응 #653780

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4-chloro-3-(4-chloro-5-dibromomethyl-2-fluorophenyl)-5-difluoromethoxy-1-methyl-1H-pyrazole

sulfuric acid

→

2-Chloro-5-(4-chloro-5-difluoromethoxy-1-methyl-1H-pyrazol-3-yl)-4-fluorobenzaldehyde

반응 조건

후처리

1. 1
   온도cooling, whereupon the mixture
2. 2
   추출The mixture was subsequently extracted three times
3. 3
   세척The combined organic phases were washed with water
4. 4
   건조dried over magnesium sulfate
5. 5
   농축finally concentrated
6. 6
   기타The crude product was purified by means of silica gel column chromatography (eluent: hexane/ethyl acetate=8:1)

실험 절차

68 g (0.14 mol) of 4-chloro-3-(4-chloro-5-dibromomethyl-2-fluorophenyl)-5-difluoromethoxy-1-methyl-1H-pyrazole were dissolved in 200 ml of concentrated sulfuric acid, with ice-cooling, whereupon the mixture was heated at 10° C. until the evolution of gas had ceased. It was then poured into 4 l of ice-water. The mixture was subsequently extracted three times using ethyl acetate. The combined organic phases were washed with water, then dried over magnesium sulfate and finally concentrated. The crude product was purified by means of silica gel column chromatography (eluent: hexane/ethyl acetate=8:1). Yield: 35 g; m.p.: 95-98° C.

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