Phenazone Impurity A (EP); 5-Methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one; 3-Methyl-1-phenyl-2-pyrazolin-5-one; 2,4-Dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one; 1-Phenyl-3-methyl-1H-4,5-dihydropyrazol-5-one; Methylphenylpyrazolone;Norantipyrine; Norphenazone; Radicut;3-Methyl-1-phenyl-2-pyrazolin-5-one; 3-Methyl-1-phenyl-1H-pyrazol-5(4H)-one; Antipyrine Related Compound A (USP);