19064-67-6 3(2H)-Pyridazinone, 6-chloro- 3-Chloro-6-hydroxypyridazine 3-Chloro-6-pyridazone 3-Hydroxy-6-chloropyridazine 6-Chloro-3(2H)pyridazinone 6-Chloro-3-hydroxypyridazine NSC75071