Crystal strucutre of rac-methyl (11aR∗,12S∗,13R∗,15aS∗,15bS∗)-11-oxo-11,11a,12,13-tetrahydro-9H,15bH-13,15a-epoxyisoindolo[1,2-c]pyrrolo[1,2-a][1,4]benzodiazepine-12-carboxylate

The title compound, C21H18N2O4, obtained as a racemate, contains a novel heterocyclic system, viz. isoindolo[1,2-c]pyrrolo[1,2-a][1,4]benzodiazepine. The central diazepane ring has a distorted boat conformation with two phenylene-fused and one methine C atom deviating by 0.931(1), 0.887(1) and 0.561(1)Å, respectively, from the mean plane of the rest of the ring. The γ-lactone ring has an envelope conformation, with the C atom opposite to amide bond deviating by 0.355(1)Å from its plane. In the crystal, molecules form centrosymmetric dimers through pairs of C-H⋯O hydrogen bonds. © 2014.