2-Methylamino-5-nitrobenzoic acid

2-Amino-5-nitrobenzoic acid

In the title compound, C₇H₆N₂O₄, an intra­molecular 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 R₂²(8) loops. Inter­molecular N—H⋯O and C—H⋯O hydrogen bonds then link the dimers, generating R₃³(16)R₂¹(6) motifs. The whole mol­ecule is essentially planar, with the greatest deviation from the mean plane being 0.065 (2) Å.

5-Chloro-2-hy-droxy-benzoic acid

The asymmetric unit of the title compound, C₇H₅ClO₃, contains two mol­ecules; both feature an intra­molecular O—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, both mol­ecules form inversion dimers linked by pairs of O—H⋯O hydrogen bonds with R₂²(8) ring motifs. The dimers are inter­linked by C—H⋯O inter­actions.