過マンガン酸カリウム
It was first synthesized by Ludwig Knorr in 1887. Phenazone is synthesized by condensation of phenylhydrazine and ethyl acetoacetate under basic conditions and methylation of the resulting intermediate compound 1-phenyl-3-methylpyrazolone with dimethyl sulfate or methyl iodide. It crystallizes in needles which melt at . Potassium permanganate oxidizes it to pyridazine tetracarboxylic acid. Phenazone has an elimination half life of about 12 hours.