Crystal structure of 4-methoxy-N-phenylbenzamide

In the title molecule, C14H13NO2, the dihedral angle between the planes of the benzene rings is 65.18 (4)°. The central amide group has about the same degree of twist with respect to both ring planes, as indicated by the dihedral angles of 34.70 (8) and 30.62 (8)° between its plane and that of the phenyl and 4-methoxybenzene rings, respectively. The C atom of the methoxy group is close to being coplanar with its attached ring [deviation = −0.112 (2) Å]. In the crystal, molecules are linked by inter-amide N—H⋯O hydrogen bonds, which generate C(4) chains propagating in the [100] direction. Adajcent molecules in the chain are related by translational symmetry.


S1. Experimental
To a 100 ml round flask fitted with a condenser was added aniline (0.93 g, 10 mmol), dichloromethane (15 ml) and triethylamine(0.5 ml) with magnetic stirring. 4-methoxybenzoyl chloride (1.70 g, 10 mmol) was added gradually. The reaction mixture was stirred at room temperature for 1 h and then refluxed for 2 h. The product precipitated as a white powder, which was washed three times with water and dichloromethane. Recrystallization from ethyl alcohol solution produced colourless prisms of the title compound.

S2. Refinement
H atoms were placed in idealized positions and allowed to ride on their respective parent atoms, with C-H = 0.93 Å, N -H = 0.86 Å and U iso (H)= 1.2U eq (C,N).

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
supporting information

Figure 2
Part of the crystal structure of (I) with the donor-acceptor distances of hydrogen bonds drawn as dashed lines. H atoms are not shown.

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.