PiperylonePiperylone is a pyrazolone with analgesic, anti-inflammatory, and antipyretic properties.SynthesisHydrazone formation of 1-methyl-4-piperidone with benzohydrazide gives. Catalytic hydrogenation using Adams' catalyst gives the substituted hydrazine after acid-catalyzed hydrolysis to remove the benzoyl group and neutralization. The pyrazolone ring is formed in a condensation reaction with ethyl 2-benzoylbutanoate, yielding piperylone.