The title compound, C13H13NO3, was synthesized by acetylation of ethyl 1H-indole-3-carboxylate. The aromatic ring system of the molecule is essentially planar, but the saturated ethyl group is also located within this plane and the overall r.m.s. deviation from planarity is only 0.034 Å. Pairs of C-HO interactions connect molecules into chains along the diagonal of the unit cell. Molecules also form weakly connected dimers via stacking interactions of the indole rings with centroid-centroid separations of 3.571 (1) Å. C-H interactions between methylene and methyl groups and the indole and benzene ring complete the directional intermolecular interactions found in the crystal structure.
T. Siddiquee, S. Islam, D. Bennett, M. Zeller and M. Hossain "Ethyl 1-acetyl-1H-indole-3-carboxylate" Acta Cryst. (2009). E65, o1802-o1803 https://doi.org/10.1107/S1600536809025379