Sulfuric Acid → 2-Chloro-5-(4-chloro-5-difluoromethoxy-1-methyl-1H-pyrazol-3-yl)-4-fluorobenzaldehyde
反応式
[Cl:1][C:2]1[C:3]([C:12]2[CH:17]=[C:16]([CH:18](Br)Br)[C:15]([Cl:21])=[CH:14][C:13]=2[F:22])=[N:4][N:5]([CH3:11])[C:6]=1[O:7][CH:8]([F:10])[F:9].S(=O)(=O)(O)[OH:24]>>[Cl:21][C:15]1[CH:14]=[C:13]([F:22])[C:12]([C:3]2[C:2]([Cl:1])=[C:6]([O:7][CH:8]([F:10])[F:9])[N:5]([CH3:11])[N:4]=2)=[CH:17][C:16]=1[CH:18]=[O:24]参加物
3
反応条件
- 温度
- 10 °C
実験手順
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.