The title compound, C8H9NO3, likely generated through hydrolysis and esterification of 3′-carboxy-3-methyl-(1,4′-bipyridin)-1-ium chloride by ethanol, which contained water, has a nearly planar conformation. The crystal structure is sustained by one-dimensional chains along the a-axis direction based on bifurcated N—H...(O,O) hydrogen bonds between the NH group of the 4-oxo-1,4-dihydropyridine ring and the two carbonyl O atoms.
