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 intra-molecular C-H⋯N inter-action, which generates an S(6) ring, helps to estalish the mol-ecular conformation. In the crystal, the mol-ecules 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 supra-molecular [001] chains. The crystal structure also features weak π-π stacking [centroid-centroid distance = 3.5943 (9) Å] and C-H⋯π inter-actions.