Experimental

R factor = 0.048; wR factor = 0.122; data-to-parameter ratio = 15.3. The molecular structure of the title compound, C13H10N2O4, shows an almost planar conformation as the benzene rings make a dihedral angle of 2.31 (7). The nitro group lies in plane with the benzamide ring, with a C—C—N—O torsion angle of 0.6 (2). In the crystal, N—H O and O—H O hydrogen bonds link molecules into sheets stacked along [101]. Related literature For background to aromatic polyimides, see: Sheng et al. (2009). For the solubilizing role of ether and amide groups in polyimides, see: Litvinov et al. (2010). For a related structure, see: Raza et al. (2010)