Synthesis and crystal structure of 1-hy­droxy-8-methyl-9H-carbazole-2-carbaldehyde

Two crystallographically independent mol­ecules are present in the asymmetric unit of the title compound, C(14)H(11)NO(2), with virtually identical geometries. The carbazole units are planar. The hy­droxy group at position 1, carbaldehyde group at position 2, and methyl group at position 8 (with the exception of two H atoms) are coplanar with the attached benzene rings. The dihedral angle between the two benzene rings is 2.20 (9)° in mol­ecule A and 2.01 (9)° in mol­ecule B. The pyrrole ring makes dihedral angles of 0.82 (10) and 1.40 (10)° [0.84 (10) and 1.18 (10)° in mol­ecule B] with the (–CH(3))-substituted and (–OH and –CHO) substituted benzene rings, respectively. The mol­ecular structure is stabilized by the intra­molecular O—H⋯O hydrogen bonds, while the crystal structure features N—H⋯O and C—H⋯O hydrogen bonds. A range of π–π contacts further stabilizes the crystal structure.