2-Pyrazolin-5-one, 3-methyl-4-phenylhydrazino- 3-Methyl-4-phenylhydrazino-2-pyrazolin-5-one 3H-Pyrazol-3-one, 2,4-dihydro-5-methyl-4-(2-phenylhydrazino)- 74037-30-2 NSC174061 WLN: T5NMV DHJ DMMR& E1