1'-Butyl-2-methyl-1',2,2',3,4,9-hexa-hydro-spiro-[benzo[f]isoindole-1,3'-indole]-2',4,9-trione.

In the title compound, C(24)H(22)N(2)O(3), the indoline and pyrrole-fused naphtho-quinone units are both essentially planar [r.m.s. deviations = 0.042 (3) and 0.133 (3) Å, respectively]. The pyrrole ring adopts a C-envelope conformation. The dihedral angle between the mean planes of the two five-membered rings is 89.94 (9)°. The O atoms deviate from the mean planes of the pyrrolidine and naphthalene rings by 0.0311 (2), 0.2570 (2) and 0.1669 (2) Å. In the crystal, C-H⋯O inter-actions generate dimers with R(2) (2)(16) and R(2) (2)(18) graph-set motifs. The carbonyl O atom is involved in bifurcated hydrogen bonding. C-H⋯π inter-actions also occur.