Crystal structure of ethyl 2′′,3-dioxo-7′,7a'-dihydro-1′H,3H,3′H-dispiro[benzo[b]thiophene-2,6′-pyrrolo[1,2-c]thiazole-5′,3′′-indoline]-7′-carboxylate

Abstract

In the title compound, C23H20N2O4S2, the central pyrrolidine ring adopts an envelope conformation with the spiro C atom, shared with the benzothiophene ring system, as the flap. The thiazole ring has a twisted conformation on the S—C bond, where the C atom is that closest to methine C atom. The mean planes of the benzothiophene and indoline ring systems are inclined to the mean plane of the central pyrrolidine ring by 82.75 (8) and 80.03 (8)°, respectively, and to each other by 61.49 (6)°. In the crystal, molecules are linked via pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8) ring motif. The dimers are linked via C—H...O and C—H...N hydrogen bonds, forming a three-dimensional structure. The ethoxycarbonyl group is disordered over two orientations, with an occupancy ratio of 0.717 (12):0.283 (12).

Keywords

• crystal structure
• dispiro
• benzothiophene
• thiazole
• pyrrolidine
• indoline
• hydrogen bonds
• inversion dimers