Synonyms: 1-Phenyl-4,5-dichloro-6-pyridazinone;1-Phenyl-4,5-dichloro-6-pyridazone;2-Phenyl-4,5-dichloro-3(2H)-pyridazinone;2-Phenyl-4,5-dichloro-3-pyridazinone;4,5-Dichloro-1-phenyl-6-pyridazone;4,5-Dichloro-1-phenylpyridazin-6(1H)-one;4,5-Dichloro-1-phenylpyridazin-6-one;4,5-Dichloro-2-phenyl-3(2H)-pyridazinone;4,5-Dichloro-2-phenylpyridazin-3-one;NSC 224369;NSC 642642;