The mol-ecule of the title compound, C(10)H(9)NO(5), is approximately planar, with the mean planes of the nitro, carboxyl and all-yloxy groups rotated by 8.1 (3), 7.9 (3) and 4.52 (18)°, respectively, from the plane of the benzene ring. Bond lengths in the aromatic ring are influenced by both electronic effects and strain induced by ortho-substitution. In the crystal structure, centrosymmetrica...

In the title compound, C(7)H(6)N(2)O(4), an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(8) loops. Inter-molecular N-H⋯O and C-H⋯O hydrogen bonds then link the dimers, generating R(3) (3)(16)R(2) (1)(6) motifs. The whole mol-ecule is essentially planar, with the greatest deviation from the ...

In the title compound, C7H6FNO2, the mol-ecule is almost planar (r.m.s. deviation for the non-H atoms = 0.015 Å) and an intra-molecular N-H⋯O hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R2(2)(8) loops. Weak N-H⋯F hydrogen bonds, short F⋯F contacts [2.763 (2) Å] and aromatic π-π stacking inter-actions [centroid-centroid sep...

In the title compound, C(13)H(10)ClNO(4)S, the dihedral angle between the aromatic ring planes is 87.07 (6)° and an intra-molecular C-H⋯O inter-action occurs. In the crystal, inversion dimers linked by two O-H⋯O hydrogen bonds arise from the carboxyl groups. N-H⋯O hydrogen bonds link the dimers into chains and short C-Cl⋯π and S-O⋯π contacts are also seen.