1,1-Dimethylethyl 3-((6-(aminocarbonyl)-3-pyridazinyl)hydrazono)butanoate 5-25-18-00047 (Beilstein Handbook Reference) 69579-17-5 BRN 0820351 Butanoic acid, 3-((6-(aminocarbonyl)-3-pyridazinyl)hydrazono)-, 1,1-dimethylethyl ester GYKI 11702