(E)-N-{2-[1-(Benzylimino)ethyl]phenyl}benzamide

In the title compound, C22H20N2O, the molecular conformation is supported by an intramolecular N—H⋯N hydrogen bond, resulting in an almost planar [mean deviation = 0.048 (2) Å] S(6) ring. The dihedral angles between the central benzene ring and the imine- and amide-substituted aromatic rings are 76.6 (2) and 11.7 (2)°, respectively.

In the title compound, C 22 H 20 N 2 O, the molecular conformation is supported by an intramolecular N-HÁ Á ÁN hydrogen bond, resulting in an almost planar [mean deviation = 0.048 (2) Å ] S(6) ring. The dihedral angles between the central benzene ring and the imine-and amide-substituted aromatic rings are 76.6 (2) and 11.7 (2) , respectively. 226 parameters H-atom parameters constrained Á max = 0.20 e Å À3 Á min = À0.17 e Å À3 Table 1 Hydrogen-bond geometry (Å , ).   et al., 2001;Chisholm et al., 2002), structurally-related ligand precursors were synthesized and examined catalytic activities in ring-opening polymerization. For instance, anilido-aldimine (AA) ligands have been designed to control the steric or electronic effect to provide a single active metal center for minimizing the side reaction. Recently, a series of N,N,N-tridentate AA rare-earth metal, magnesium and zinc complexes have demonstrated that the nitrogen atom of pendant arm can coordinate with the metal to increase the sterics and coordination sites of the ligand, creating a single active site nature to initiate the polymerization of ε-caprolactone and L-lactide (Gao et al., 2008;Tsai et al., 2009). In order to investigate ligand precursors bearing similar chelating systems and iso-electronic features related to anilido-aldimine ligands, our group is interested in developing new AA-like ligands from the aminoacetophenone derivatives. Herein, we report the synthesis and crystal structure of the title compound, (I), a potential N,N,O-tridentate AA-like ligand for the preparation of aluminum, magnesium and zinc complexes (Scheme 1).

Related literature
The solid structure of I reveals the phenyl configuration containing one benzamide functionalized group and one benzyl substituted imine group on the ortho-position (Fig. 1). It was found that there is an intramolecular N-H···N hydrogen bond between the amide and imine groups. The distance of N···H is substantially shorter than the van der Waals distance of 2.75Å for the N and H atoms. It is interesting to note that the six-member ring (N1/C9/C10/C15/N2/H2B) formed from the N-H···N hydrogen-bond is almost coplanar with the mean deviation of 0.048 (2)Å. These bond distances of benzyl substituted imine group are similar to those found in the crystal structure of (E)-N-(2-((benzylimino)methyl)phenyl)-2,6-diisopropylaniline (Liu et al., 2009).

Experimental
The title compound I was synthesized by the following procedures ( Fig. 2): In a 50 ml round bottom flask, benzoyl chloride (15.5 g, 110.7 mmol) was added to a solution of 2'-aminoacetophenone, (1) (10.0 g, 74.1 mmol) dissolved in 5% NaOH (aq) solution (20 ml). The mixture was stirred vigorously for 2 h and the resultant precipitate was washed with dichloromethane (3×50 ml), followed by deionized water (2×50 ml). The organic layer was dried over anhydrous magnesium sulfate and the solvent was dried under vacuum

Refinement
The H atoms were placed in idealized positions and constrained to ride on their parent atoms, with C-H = 0.93Å with U iso (H) = 1.2 U eq (C) for phenyl hydrogen; 0.96Å with U iso (H) = 1.5 U eq (C) for CH 3 group; 0.97Å with U iso (H) = 1.2 U eq (C) for CH 2 group; N-H = 0.86Å with U iso (H) = 1.2 U eq (N).

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 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 Rfactors(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.