Ethyl 4-hydr­oxy-9-tosyl-9H-carbazole-3-carboxyl­ate

In the title compound, C(22)H(19)NO(5)S, the carbazole skeleton is nearly planar [maximum deviation = 0.043 (1) Å] with the pyrrole ring oriented at dihedral angles of 2.32 (6) and 1.77 (6)° with respect to the adjacent benzene rings. The dihedral angle between the benzene ring of the tosyl group and the carbazole skeleton is 82.25 (5)°. Intra­molecular O—H⋯O hydrogen bonding results in the formation of a planar six-membered ring, which is oriented at a dihedral angle of 3.06 (4)° with respect to the adjacent carbazole skeleton. In the crystal structure, weak inter­molecular C—H⋯O inter­actions link the mol­ecules into infinite chains and π–π contacts between the benzene rings and between the pyrrole and benzene rings [centroid–centroid distances = 3.374 (1) and 3.730 (1) Å, respectively] may further stabilize the structure. A weak C—H⋯π inter­action is also present.