7′-(4-Bromophenyl)-5′,6′,7′,7a’-tetrahydrodispiro[indan-2,5′-pyrrolo[1,2-c][1,3]thiazole-6′,2′′-indan]-1,3,1′′-trione

In the title compound, C28H20BrNO3S, the thiazolidine, pyrrolidine and two five-membered carbocyclic rings are in envelope conformations. The bromo-bound phenyl ring forms dihedral angles of 61.97 (18) and 88.30 (17)° with the other two benzene rings. The two benzene rings form a dihedral angle of 30.3 (2)°. The molecular structure features an intramolecular C—H⋯O hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked into inversion dimers by pairs of C—H⋯O hydrogen bonds.

In the title compound, C 28 H 20 BrNO 3 S, the thiazolidine, pyrrolidine and two five-membered carbocyclic rings are in envelope conformations. The bromo-bound phenyl ring forms dihedral angles of 61.97 (18) and 88.30 (17) with the other two benzene rings. The two benzene rings form a dihedral angle of 30.3 (2) . The molecular structure features an intramolecular C-HÁ Á ÁO hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked into inversion dimers by pairs of C-HÁ Á ÁO hydrogen bonds.

Refinement
All H atoms were positioned geometrically and refined using a riding model with C-H = 0.93-0.98 Å and U iso (H) = 1.2 U eq (C). Fig. 1. The molecular structure of the title compound showing 30% probability displacement ellipsoids for non-H atoms. Intramolecular hydrogen bond is shown as dashed line.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq