2-(1H-Benzimidazol-2-yl)-4-nitrophenol

The title compound, C13H9N3O3, was prepared by the reaction of 5-nitrosalicylaldehyde with 1,2-diaminobenzene in methanol. The whole molecule is approximately planar, with a mean deviation from the plane defined by the non-H atoms of 0.0311 (4) Å, and with a dihedral angle between the benzene ring and the benzimidazole ring system of 1.1 (3)°. An intramolecular O—H...N hydrogen bond occurs. In the crystal, adjacent molecules are linked through intermolecular N—H...O hydrogen bonds, forming centrosymmetric dimers.