Ethyl 1-benzyl-1,2,3,3a,4,10b-hexahydropyrrolo[2′,3′:3,4]pyrrolo[1,2-a]benzimidazole-2-carboxylate

The title molecule, C22H23N3O2, was obtained via an intramolecular cycloaddition of an azomethine ylide and an alkene tethered by a benzimidazole unit. The benzoimidazole unit is essentially planar, with an r.m.s. deviation of 0.0087 from the nine constituent atoms. It has a cis fusion of the two pyrrolidine rings as well as a cis ester appendage. The two pyrrolidine rings rings have envelope conformations. The crystal packing is stabilized by aromatic π–π stacking of parallel benzimidazole ring systems, with a centroid-to-centroid distance of 3.518 (6) . Weak intermolecular C—H...O contacts may also play a role in the stability of the packing.