Dimethyl­ammonium 5-carb­oxy-2-(1-oxo-1λ(5)-pyridin-2-yl)-1H-imidazole-4-car­box­yl­ate

In the title salt, C(2)H(8)N(+)·C(10)H(6)N(3)O(5) (−), the imidazole­carboxyl­ate anion is essentially planar [maximum deviation from the least-squares plane = 0.046 (5) Å], with a dihedral angle between the rings of 2.7 (2)°. This conformation is maintained by the presence of both intra­molecular carb­oxy–carboxyl­ate O—H⋯O and imidazole–oxide N—H⋯O hydrogen bonds. Iin the crystal, cation–carboxyl­ate N—H⋯O and cation–imidazole N—H⋯N hydrogen bonds result in chains along the b axis.