Hydrochloric Acid → 2-(4-Fluorophenyl)-1-[4-(methylthio)phenyl]-4,4,4-trifluoro-1,3-butanedione

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Reaction Steps

A mixture of 4.0 g of product of step 1, 40 mL of ether, and 40 mL of 6N hydrochloric acid was stirred at room temperature for 4 days. The ether layer was dried over magnesium sulfate and concentrated in vacuo to give 4.0 g of crude 2-(4-fluorophenyl)-1-[4-(methylthio)phenyl]-4,4,4-trifluoro-1,3-butandione. A mixture of 0.22 g (0.59 mmol) of this product, 0.09 g of phenylhydrazine, and 10 mL of glacial acetic acid was heated at 80° C. for 18 hours and poured into water. The insoluble solid was purified by HPLC (10% ethyl acetate-hexane) to give 8 mg of 4-(4-fluorophenyl)-3-[4-(methylthio)phenyl]-1-phenyl-5-(trifluoromethyl)pyrazole and 140 mg of 4-(4-fluorophenyl)-5-[4-(methylthio)phenyl]-1-phenyl-3-(trifluoromethyl)pyrazole.

Provenance & Evidence