Crystal structure of methyl (E)-2-(1-methyl-2-oxoindolin-3-yl-idene)acetate.

The title compound, C12H11NO3, is essentially planar, with the mean plane of the acetate side chain [-C-C(=O)-O-C] being inclined to the mean plane of the indole ring system by 12.49 (7)°. The five- and six-membered rings of the indole group are almost coplanar, making a dihedral angle of 1.76 (8)°. The conformation about the C=C bond is E and there is an intra-molecular C-H⋯O hydrogen bond present. In the crystal, mol-ecules are linked by pairs of C-H⋯O hydrogen bonds forming inversion dimers, with an R 2 (2)(16) ring motif. The dimers are linked by a second pair of C-H⋯O hydrogen bonds, enclosing R 2 (2)(16) ring motifs, forming ribbons lying parallel to (-114). The ribbons are linked via C-H⋯π inter-actions, forming a three-dimensional structure.