Ethanol → 1-(2-Fluoro-4-chloro-5-methylsulfonyloxyphenyl)-3,4,5-trimethylpyrazole

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Reaction Steps

A mixture of (2-fluoro-4-chloro-5-methylsulfonyloxyphenyl)hydrazine (25.5 g) of the formula: ##STR53## 3-methylpenta-2,5-dione (CH3COCH(CH3)COCH3) (11.4 g), ethanol (100 ml) and water (100 ml) was heated to reflux for one hour. After the reaction mixture was cooled, toluene was added thereto to form two layers. The toluene layer separated was washed with water and dried over anhydrous sodium sulfate. Removal of the solvent by distillation in vacuo gave the titled compound (29.3 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. 123°-125° C.

Provenance & Evidence