1-Fenyl-4,5-dichlor-6-pyridazinon 1698-53-9 3(2H)-Pyridazinone, 4,5-dichloro-2-phenyl- 4,5-Dichloro-2-phenylpyridazin-3-one NSC224369 WLN: T6NNVJ BR& DG EG