(±)-trans-5-Benzoyl-4-(3-bromophenyl)-2-(1H-indol-3-yl)-4,5-dihydrofuran-3-carbonitrile

The furan ring in the title compound, C26H17BrN2O2, adopts a twisted envelope conformation. The molecular structure is stabilized by an intramolecular C—H⋯O interaction which generates an S(6) ring motif. The crystal packing is stabilized by N—H⋯O and C—H⋯Br interactions, generating an R 2 2(16) ring motif and a C(12) linear chain motif, respectively. Weak C—H⋯π bonding is also observed.

The furan ring in the title compound, C 26 H 17 BrN 2 O 2 , adopts a twisted envelope conformation. The molecular structure is stabilized by an intramolecular C-HÁ Á ÁO interaction which generates an S(6) ring motif. The crystal packing is stabilized by N-HÁ Á ÁO and C-HÁ Á ÁBr interactions, generating an R 2 2 (16) ring motif and a C(12) linear chain motif, respectively. Weak C-HÁ Á Á bonding is also observed.
Cg1 and Cg2 are the centroids of the C51-C56 and C32-C37 rings, respectively. Symmetry codes: (i) Àx þ 1; Ày þ 1; Àz þ 1; (ii) x þ 1; y; z þ 1; (iii) x À 1 2 ; Ày À 1 2 ; z À 1 2 ; (iv) x À 1; y; z.  Furan derivatives have calplain-inhibiting activity and are used in the preparation of medicaments for the treatment of inflammatory and immunological diseases, cardiovascular and cerebro-vascular diseases, disorders of the central or peripheral nervous system, cachexia, osteoporosis, muscular dystrophy, proliferative diseases, cataracts, rejection reactions following organ transplants and auto-immune and viral diseases (Auvin & Chabrier De Lassauniere, 2005). In view of the high medicinal value of these compounds in conjunction with our research interest, prompted us to synthesize and report the X-ray studies of the title compound in this paper.
The molecular structure is stabilized by an intramolecular C-H···O interaction which generates an S(6) ring motif (Bernstein et al., 1995). The presence of N-H···O hydrogen bonds leads to inversion dimers which are stabilized in the crystal packing by C-H···Br and C-H···π interactions, Table 1.

Refinement
H atoms were placed at calculated positions and allowed to ride on their carrier atoms with C-H = 0.93-0.98 Å, and with U iso = 1.2U eq (C). The N-bound H atom was located in a difference Fourier map and refined freely.  The molecular structure of (I), showing 40% probability displacement ellipsoids and the atom-numbering scheme.

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