2-(2-{[2-(4-Pyridylcarbon­yl)hydrazinyl­idene]meth­yl}phen­oxy)acetic acid

In the title compound, C₁₅H₁₃N₃O₄, the pyridine and benzene rings are nearly perpendicular [dihedral angle = 84.24 (5)°]. In the crystal structure, classical O—H...N hydrogen bonding between the OH group of the carboxyl unit and a neighbouring pyridine ring N atom and N—H...O hydrogen bonding between the imine NH group and a neighbouring O atom of an acyl unit, together with complementary non-classical C—H...O hydrogen bonds between carboxyl O atoms and neighbouring CH groups, link the mol­ecules into a three-dimensional system.