3-[(1-Isobutyl-1H-imidazo[4,5-c]quinolin-4-yl)amino]­benzoic acid

In the title compound, C(21)H(20)N(4)O(2), the statistically planar 1H-limidazole ring [maximum deviation = 0.003 (1) Å] makes dihedral angles of 1.33 (9) and 8.23 (7)°, respectively, with the essentially planar fused pyridine ring [maximum devation = 0.018 (1) Å] and the pendant benzene ring, which is attached to the pyridine ring by an —NH— group. An intra­molecular C—H⋯N inter­action, which generates an S(6) ring, helps to estalish the mol­ecular conformation. In the crystal, the mol­ecules are linked by N—H⋯O, C—H⋯O and O—H—N hydrogen bonds, which generate bifurcated R (1) (2)(6) and R (2) (2)(9) ring motifs, resulting in supra­molecular [001] chains. The crystal structure also features weak π–π stacking [centroid–centroid distance = 3.5943 (9) Å] and C—H⋯π inter­actions.