4,4'-dihydroxyantipyrine

2,3-Dihydro-4-hydroxy-1,5-dimethyl-2-(4-hydroxyphenyl)-1H-pyrazol-3-one

3H-Pyrazol-3-one, 1,2-dihydro-4-hydroxy-2-(4-hydroxyphenyl)-1,5-diMethyl-