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

The title mol­ecule, C(22)H(23)N(3)O(2), 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 Å 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) Å. Weak inter­molecular C—H⋯O contacts may also play a role in the stability of the packing.