3(2H)-Pyridazinone, 6-(2-ethyl-1H-imidazol-1-yl)-, hydrazone, hydrate (2:1) 3-Hydrazino-6-(2-ethylimidazol-1-yl)pyridazine hemihydrate 6-(2-Ethyl-1H-imidazol-1-yl)-3(2H)-pyridazinone hydrazone hydrate (2:1) 75792-68-6