N-Benzyl-N-(4-chlorophenyl)acrylamide

In the molecular structure of the title compound, C16H14ClNO, the acrylamide unit is essentially planar and makes dihedral angles of 80.06 (12) and 68.91 (13)°, respectively, with the benzene and phenyl rings. The dihedral angle between the two rings is 49.79 (11)°. In the crystal structure, molecules are connected via weak C—H⋯O and C—H⋯π interactions, forming a molecular tape running along the b axis.

In the molecular structure of the title compound, C 16 H 14 ClNO, the acrylamide unit is essentially planar and makes dihedral angles of 80.06 (12) and 68.91 (13) , respectively, with the benzene and phenyl rings. The dihedral angle between the two rings is 49.79 (11) . In the crystal structure, molecules are connected via weak C-HÁ Á ÁO and C-HÁ Á Á interactions, forming a molecular tape running along the b axis.

Comment
Many active molecules in nature contain highly functionalized heterocyclic rings (Fairlamb, 2004). In recent research, we report a novel palladium catalyzed Heck intermolecular reactions of aryl halides with the nitron-containing olefins (Hu et al., 2003). We found that polyene amide was prepared by two steps (Riggi et al., 1992). The substrate of N-benzyl-N-(4chlorophenyl)acrylamide is used to obtain this pyrrole skeleton (Park & Hoffmann, 1990;Otero & Cantero, 1995).
In this paper, we report the crystal structure of the title compound, C 16 H 14 ClNO (Fig. 1). The crystal data show that all bond lengths and angles in the title compound have normal values. The bond length of C15=C16 is 1.288 (4) Å, belonging to typical C sp2 -C sp2 double bonds. The molecule contains two six-membered rings, A (C1-C6) and B (C8-C13). Rings A and B are not coplanar, the dihedral angle between ring A and ring B being 49.79 (11)

Experimental
The solution of 4-chlorobenzenamine (12.75 g, 0.1 mol) and triethylamine (14 ml, 0.1 mol) in CCl 4 (20 ml) was placed in a three-necked flask equipped with reflux condenser, dropping funnel and mechanical stirrer. The 1-chloromethylbenzene (13.91 g, 0.11 mol) in CCl 4 (20 ml) was added at a rate such as to produce gentle reflux at room temperature. The crude product was recrystallized from C 2 H 5 OH; yield (21.54 g, 90%). N-benzyl-4-chlorobenzenamine (10.89 g, 0.05 mol) was stirred at ice-water in the presence of 2-propenoyl chloride (4.9 ml, 0.06 mol) and triethylamine (8.4 ml, 0.06 mol) in CCl4 (20 ml). The mixture was washed with water and the organic layer was dried by MgSO 4 . The crude product was purified by flash column chromatography on silica gel (light petroleum/EtOAc, 8:1) to obtain the product (8.23 g, 61%). Colorless crystals of the N-benzyl-3-(4-chlorophenyl)-3-phenyl-propanamide suitable for X-ray diffraction were obtained from an ethyl acetate solution over one week.

Refinement
H atoms were placed in calculated positions with C-H distances 0.93-0.97 Å and treated as riding, with U iso (H) = 1.2U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids with numbering scheme.   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 C1 0.1090 (