5-Carboxy-1,3-bis(carboxymethyl)-4-imidazolinium-4-carboxylate

The title compound, C9H8N2O8, was obtained by the reaction of imidazole-4,5-dicarboxylic acid and 2-chloroacetic acid. An intramolecular O—H...O hydrogen bond occurs. The crystal packing is stabilized by intermolecular O—H...O and C—H...O hydrogen bonds, which link molecules into a three-dimensional network.