[2-Benzyl-3-(naphthalen-1-yl)-2,3-dihydro-1,2-oxazole-4,5-diyl]bis(phenylmethanone)

In the title compound, C34H25NO3, the five-membered heterocyclic ring adopts an envelope conformation with the N atom as the flap. The plane through the four basal atoms of this ring makes dihedral angles of 69.78 (13), 53.15 (12) and 86.42 (13)°, respectively, with the benzene rings of the benzyl group and the two phenylmethanone groups at the 4 and 5 positions, and of 78.60 (11)° with the naphthalenyl system. In the crystal, the molecules are linked through C—H⋯O and C—H⋯π contacts into layers parallel to (101).

In the title compound, C 34 H 25 NO 3 , the five-membered heterocyclic ring adopts an envelope conformation with the N atom as the flap. The plane through the four basal atoms of this ring makes dihedral angles of 69.78 (13), 53.15 (12) and 86.42 (13) , respectively, with the benzene rings of the benzyl group and the two phenylmethanone groups at the 4 and 5 positions, and of 78.60 (11) with the naphthalenyl system. In the crystal, the molecules are linked through C-HÁ Á ÁO and C-HÁ Á Á contacts into layers parallel to (101).  Table 1 Hydrogen-bond geometry (Å , ).
The compound crystallizes in the monoclinic space group P2 1 /n. The dihedral angles between the three aromatic six- One of the above interaction (C5-H5···O1) forms a centerosymmetric dimer with the adjacent molecule while the other connects such dimers together to build a molecular chain (Fig. 3) in the lattice. An intermolecular C-H···π interaction (Fig. 4) between the H at C13 and the C1-C6 aromatic ring of the neighbouring molecule with H···π distance of 2.63 Å interconnects the molecular chains together. Thus, these intermolecular hydrogen bonding interactions augmented by a C-H···π interaction play a major role to form a supramolecular network in the lattice of the molecular system. Similar intermolecular interactions are found in the compound (2-tert-butyl-3-phenyl-2,3-dihydroisoxazole-4,5-diyl)bis(phenylmethanone) (Sandhya et al., 2013). Fig. 5 shows the packing diagram of the title compound along a axis.

Experimental
The title compound was prepared by adapting a reported procedure (Chakraborty et al., 2012). N-naphthylidene-Nbenzylnitrone, (3 mmol) and dibenzoylacetylene (3 mmol) were added into 15 mL of acetonitrile and stirred for 4 h at room temperature. The reaction was monitored by TLC using EtOAc/hexane (1:5). The solvent was removed under reduced pressure and the product was purified from the crude by column chromatography on silica gel. Colourless crystals suitable for X-ray structure determination were grown from ethanol by slow evaporation (m.p: 134 °C).

Refinement
All H atoms on C were placed in calculated positions, guided by difference maps, with C-H bond distances of 0.93-0.98 Å. H atoms were assigned U iso =1.2U eq (carrier) or 1.5Ueq (methyl C). Omitted owing to bad disagreement was the sup-2 . E70, o354-o355 reflection (-1 0 1).     C-H···O intermolecular hydrogen bonding connecting dimers into layers.

Figure 5
Packing diagram of the compound along the a axis. 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.