Crystal structure of ethyl 1',1''-dimethyl-2'',3-dioxo-3H-di-spiro-[benzo[b]thio-phene-2,3'-pyrrolidine-2',3''-indoline]-4'-carboxyl-ate

In the title compound, C23H22N2O4S, the pyrrolidine ring has an envelope conformation with the spiro C atom, shared with the indoline ring system, as the flap. The mean planes of the benzo-thio-phene and indoline ring systems are inclined to the mean plane of the pyrrolidine ring by 88.81 (8) and 79.48 (8)°, respectively, and to each other by 68.12 (5)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming chains propagating along [001].