4-Methoxy-N-(4-methoxy-2-nitrophenyl)benzamide

In the title compound, C15H14N2O5, the central amide C—C(=O)—N—C unit forms dihedral angles of 28.17 (13) and 26.47 (13)° with the two benzene rings, whereas the two benzene rings are almost coplanar, making a dihedral angle of 4.52 (13)°. The two methoxy and the nitro substituents are almost coplanar with their attached benzene rings, with C—O—C—C torsion angles of −1.3 (4) and −4.6 (4)°, and an O—N—C—C torsion angle of 17.1 (3)°. In the crystal, molecules are linked via C—H⋯O and N—H⋯O interactions, forming a tape running along the b axis.

In the title compound, C 15 H 14 N 2 O 5 , the central amide C-C( O)-N-C unit forms dihedral angles of 28.17 (13) and 26.47 (13) with the two benzene rings, whereas the two benzene rings are almost coplanar, making a dihedral angle of 4.52 (13) . The two methoxy and the nitro substituents are almost coplanar with their attached benzene rings, with C-O-C-C torsion angles of À1.3 (4) and À4.6 (4) , and an O-N-C-C torsion angle of 17.1 (3) . In the crystal, molecules are linked via C-HÁ Á ÁO and N-HÁ Á ÁO interactions, forming a tape running along the b axis.   Table 1 Hydrogen-bond geometry (Å , ).

Experimental
The title compound was synthesized by using the following procedure. To the stirring solution of 4-methoxy-2-nitroaniline (2.97 mmol) in 6.5 ml dichloromethane, p-methoxybenzoyl chloride (8.12 mmol) and triethylamine (0.5 ml) were added carefully at room temperature. The progress of reaction was checked by TLC and was completed in 12 h. Then the reaction mixture was diluted with water (25 ml) and acidified with 1.0 M HCl (50 ml). The organic compound was extracted with ethyl acetate (2×25 mL) and washed with brine (50 ml). The organic layer was dried (anhyd. MgSO 4 ), filtered and concentrated on rotavapor. The crude mixture was purified by silica gel column chromatography by using ethyl acetate and hexane to get title compound with 77% yield. After column chromatography, the pure compound was left overnight. The crystals obtained were found suitable for single-crystal X-ray diffraction studies. All chemicals were purchased from Sigma-Aldrich and Alfa Aesar.

Refinement
The H atom on the nitrogen was located in a difference Fourier maps and refined freely [N-H = 0.80 (3) Å]. Other H atoms were positioned geometrically with 0.93 or 0.96 Å and constrained to ride on their parent atoms with U iso (H) = 1.2U eq (C) or 1.5U eq (methyl C). A rotating group model was applied to the methyl groups.

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

Figure 2
The crystal packing of the title compound. Hydrogen atoms are omitted for clearity. Dashed lines indicate the C-H···O and N-H···O hydrogen bonds.

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.