1,2-Dichloroethane → 1-(Diethylcarbamoyl)-3-(2-methyl-3-chlorophenylsulfonyl)-4-formylpyrazole

Participants

Reaction Steps

0.77 g of 3-chloroperoxybenzoic acid was added to a solution of 0.57 g of 1-(diethylcarbamoyl)-3-(2-methyl-3-chlorophenylthio)-4-formylpyrazole [prepared as described in step (2) above] in 15 ml of 1,2-dichloroethane, and the resulting mixture was stirred at room temperature for 10 hours. The reaction mixture was then mixed with an aqueous solution of sodium sulfite and extracted with methylene chloride. The extract was washed with an aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous sodium sulfate and concentrated by evaporation under reduced pressure. The concentrate was purified by column chromatography through silica gel, eluted with an 8:1 by volume mixture of hexane and ethyl acetate, to afford 198 mg (yield 32%) of the title compound, melting at 95°-97° C.

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