Triethylamine → HCID 12813186, compound

Participants

Reaction Steps

A 5.5 gram portion of the atropic ester of Example 1 was combined with 3.5 grams of 4-fluorophenylhydrazine hydrochloride and 2 grams triethylamine in 50 ml. benzene. The mixture was stirred at reflux temperature for 5 hours, after which about half of the benzene was allowed to evaporate and an equivalent amount of meta-xylene was added. The mixture was then stirred at reflux overnight, and the reaction mixture was evaporated to dryness under vacuum. The residue was partitioned between ethyl acetate and water, and the organic layer was dried over sodium sulfate and evaporated to dryness. The residue was chromatographed on silica gel with ethyl acetate as the eluant. The product containing fractions were combined and evaporated to dryness to produce about 3.5 grams of crude intermediate, which was recrystallized from methanol to produce 2.7 grams of purified 1-(4-fluorophenyl)-4-(α,α,α-trifluoro-3-tolyl)-3-pyrazolin-5-one, m.p. 171°-173° C.

Provenance & Evidence