1H-Pyrazol-5(4H)-one, 4-(2-(4-ethoxy-2-nitrophenyl)hydrazinylidene)-1-hydroxymethyl-3-methyl- 4-(2-(4-Ethoxy-2-nitrophenyl)hydrazinylidene)-1-hydroxymethyl-3-methyl-1H-pyrazol-5(4H)-one 4-(4-Ethoxy-2-nitrophenyl)hydrazono-1-hydroxymethyl-3-methyl-2-pyrazolin-5-one UR0550000