5-Chloro-5′′-[4-(dimethylamino)benzylidene]-4′-[4-(dimethylamino)phenyl]-1′,1′′-dimethyldispiro[indoline-3,2′-pyrrolidine-3′,3′′-piperidine]-2,4′′-dione

The title compound, C34H38ClN5O2, has spiro links connecting the pyrrolidine ring and indole residue, as well as the piperidine and pyrrolidine rings. A half-chair conformation is found for the piperidine ring with the C atom connected to the spiro-C atom lying 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å). The methylene C atom is the flap in the envelope conformation for the pyrrolidine ring. In the crystal, supramolecular chains are sustained by alternating eight-membered {⋯HNCO}2 and 14-membered {⋯HC5O}2 synthons. Chains are connected into a three-dimensional network by (pyrrolidine-bound phenyl-methyl)C—H⋯π(pyrrolidine-bound phenyl) edge-to-face interactions.

The title compound, C 34 H 38 ClN 5 O 2 , has spiro links connecting the pyrrolidine ring and indole residue, as well as the piperidine and pyrrolidine rings. A half-chair conformation is found for the piperidine ring with the C atom connected to the spiro-C atom lying 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å ). The methylene C atom is the flap in the envelope conformation for the pyrrolidine ring. In the crystal, supramolecular chains are sustained by alternating eight-membered {Á Á ÁHNCO} 2 and 14-membered {Á Á ÁHC 5 O} 2 synthons. Chains are connected into a three-dimensional network by (pyrrolidine-bound phenylmethyl)C-HÁ Á Á(pyrrolidine-bound phenyl) edge-to-face interactions.   Table 1 Hydrogen-bond geometry (Å , ).

Related literature
Cg1 is the centroid of the C27-C32 ring.

Refinement
The C-bound H atoms were geometrically placed (C-H = 0.93-0.98 Å) and refined as riding with U iso (H) = 1.2-1.5U eq (C). The N-bound H-atom was treated similarly with N-H = 0.86 Å, and with U iso (H) = 1.2U eq (N).

Results and discussion
In continuation of our biological and crystallographic studies of spiropyrrolidine derivatives derivatives (Girgis et al. 2012;Ahmed Farag et al. 2013a), which are known to to have biological activity (Kumar et al. 2008), the title compound, (I), was synthesised and characterised crystallographically.
The molecular structure of (I) is shown in Fig. 1 which shows two spiro links, i.e. at atom C1, linking the piperidine and pyrrolidine rings, and at atom C6 where the pyrrolidine ring and indole residue are connected. The piperidine ring carries phenylmethylidene and pyrrolidine-bound aryl residues at positions C4 and C8, respectively. An E conformation is found the C4═C11 double bond. The piperidine-N1 atom has sp 3 character as seen by the sum of the angles at this atom of 337 °. A half-chair conformation is found for the piperidine ring in which the C2 atom lies 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å). With respect to the piperidine ring, both the N-bound methyl and phenylmethylidene substituents occupy equatorial positions . An envelope conformation is found for the pyrrolidine ring with the C7 being the flap atom lying 0.547 (5) Å out of the plane of the remaining four atoms which have a r.m.s. deviation of 0.0906 Å. The similarity of the molecular structures of (I) and recently described derivatives (Ahmed Farag et al. 2013a,b), at least in terms of the cores of these, is emphasised in the overlay diagram, Fig. 2.

Figure 3
A view of the unit-cell contents in projection down the a axis in (I). The N-H···O and π-π interactions are shown as orange and purple dashed lines, respectively. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.15 e Å −3 Δρ min = −0.20 e Å −3 Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.