Experimental

R factor = 0.035; wR factor = 0.097; data-to-parameter ratio = 15.3. In the title compound, C29H29BrN2O3, the indole ring system is essentially planar (r.m.s. deviation = 0.079 Å) and makes a dihedral angle of 85.23 (10) with the mean plane of the 4-methylpyrrolidine ring. This ring adopts an envelope confor-mation with the N atom at the flap. The pyrrolidine ring of the indole ring system adopts a twisted conformation on the C— C ( O) bond. The molecular structure is stabilized by an intramolecular C—H O hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked via pairs of C—H O hydrogen bonds, forming inversion dimers with an R2 2(14) ring motif. These dimers are further linked by N— H O and C—H O hydrogen bonds, forming two-dimen-sional networks lying parallel to (101). Related literature For the biological activity of spiro-pyrrolidine derivatives, see: Obniska et al. (2002); Saito et al. (1991); Hilton et al. (2000). For related crystal structures, see: Jagadeesan et al. (2013). For puckering parameters, see: Cremer & Pople (1975). For graph-set motif notations, see: Bernstein et al. (1995). For bond-length distortions in small rings, see: Allen (1981)