3-(2-(6-Chloro-3-pyridazinyl)hydrazinylidene)valeric acid ethyl ester 5-25-17-00363 (Beilstein Handbook Reference) 69578-89-8 BRN 0920184 GYKI 11640 Pentanoic acid, 3-((6-chloro-3-pyridazinyl)hydrazono)-, ethyl ester Valeric acid, 3-(2-(6-chloro-3-pyridazinyl)hydrazinylidene)-, ethyl ester