3(2H)-Pyridazinone, 6-(1H-pyrrol-1-yl)-, hydrazone, monohydrochloride 3-Hydrazino-6-(1-pyrrolyl)pyridazine monohydrochloride 75792-80-2 Pyridazine, 3-hydrazino-6-(1-pyrrolyl)-, monohydrochloride