The molecule is a monocarboxylic acid anion arising from deprotonation of the carboxy and enol groups of 5-amino-4-chloro-2-(2-hydroxymuconoyl)pyridazin-3(2H)-one; major species at pH 7.3. It is a conjugate base of a 5-amino-4-chloro-2-(2-hydroxymuconoyl)pyridazin-3(2H)-one.
(2E,4Z)-6-(4-amino-5-chloro-6-oxopyridazin-1-yl)-5-oxido-6-oxohexa-2,4-dienoate