1,1-Dimethylethyl 3-((6-chloro-3-pyridazinyl)hydrazono)butanoate 5-25-17-00363 (Beilstein Handbook Reference) 69578-92-3 BRN 0921323 Butanoic acid, 3-((6-chloro-3-pyridazinyl)hydrazono)-, 1,1-dimethylethyl ester GYKI 11653