4-Ethylamino-3-nitrobenzoic acid

In the title compound, C9H10N2O4, an intramolecular N—H⋯O hydrogen-bond interaction generates an S(6) ring motif. The nitro group is slightly twisted away from its attached benzene ring [dihedral angle = 15.29 (15)°]. In the crystal structure, molecules are stacked down the a axis caused by short O⋯O(−1−x, −y, 2−z) contacts of 2.6481 (16) Å involving the O atoms of the nitro groups. The crystal packing is consolidated by intermolecular O—H⋯O hydrogen bonds, linking the molecules into centrosymmetric dimers.