Ethyl 1-oxo-1,2,3,4-tetra-hydro-9H-carbazole-3-carboxyl-ate

The title compound, C₁₅H₁₅NO₃, contains a carbazole skeleton with an ethoxy-carbonyl group at the 3 position. In the indole ring system, the benzene and pyrrole rings are nearly coplanar, forming a dihedral angle of 1.95 (8)°. The cyclo-hexenone ring has an envelope conformation. In the crystal structure, pairs of strong N - H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers with R ² 2(10) ring motifs. π-π contacts between parallel pyrrole rings [centroid-centroid distance = 3.776 (2) Å] may further stabilize the structure. A weak C - H⋯π inter-action is also observed.