Experimental

R factor = 0.050; wR factor = 0.138; data-to-parameter ratio = 21.1. In the title compound, C30H28N4O, the central pyrrolidine ring adopts an envelope conformation with the CH2 C atom as the flap. The quinoxaline and indene ring systems are planar, with r.m.s. deviations of 0.0165 and 0.0181 Å, respectively. The pyrrolidine ring mean plane forms dihedral angles of 88.84 (1) and 86.14 (1) with the quinoxaline and indene ring systems, respectively. A weak intramolecular C—H N interaction is observed. In the crystal, C—H O interactions lead to helical supramolecular chains along the b axis having a C(9) motif. Related literature For the importance of spiro compounds, see: Kobayashi et al. (1991); James et al. (1991). For the importance of pyrrolidine derivatives, see: Amal Raj et al. (2003). For conformation analysis, see: Cremer & Pople (1975). For a related structure, see: Selvanayagam et al. (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995)