Hydrochloric Acid → 1-(2-Fluoro-4-chloro-5-hydroxyphenyl)-3,5-dimethyl-4-nitropyrazole

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Reaction Conditions

Reaction Steps

A mixture of 1-(2-fluoro-4-chloro-5-methylsulfonyloxyphenyl)-3,5-dimethyl-4-nitropyrazole (36.5 g), 2N aqueous sodium hydroxide solution (100 ml) and ethanol (50 ml) was stirred at 40° C. for 30 minutes. After cooling, the reaction mixture was acidified with an aqueous hydrochloric acid solution and extracted with toluene. The toluene layer thus obtained was washed with water and dried over anhydrous sodium sulfate. Removal of the solvent by distillation in vacuo gave the titled compound (28.1 g) as a pale yellow crystalline solid. Recrystallization of this solid from a mixture of n-hexane and ethyl acetate afforded a white crystalline solid. m.p. 157°-158° C.

Provenance & Evidence