N-(4,6-Dimethoxypyrimidin-2-yl)-2-(3-methylphenyl)acetamide

In the title compound, C15H17N3O3, the dihedral angle between the pyrimidine and benzene rings is 87.0 (7)°. In the crystal, molecules are linked into inversion dimers with R 2 2(8) graph-set motifs by a pair of N—H⋯O hydrogen bonds. Weak C—H⋯O hydrogen bonds and intermolecular π–π interactions [centroid–centroid distance = 3.544 (1) Å] are also observed.

In the title compound, C 15 H 17 N 3 O 3 , the dihedral angle between the pyrimidine and benzene rings is 87.0 (7) . In the crystal, molecules are linked into inversion dimers with R 2 2 (8) graph-set motifs by a pair of N-HÁ Á ÁO hydrogen bonds. Weak C-HÁ Á ÁO hydrogen bonds and intermolecularinteractions [centroid-centroid distance = 3.544 (1) Å ] are also observed.

Experimental
To a stirred solution of (3-methylphenyl)acetic acid (1 g, 6.65 mmol), triethylamine (1.34 g, 13.31 mmol) and 4,6-dimethoxypyrimidin-2-amine (1.02 g, 6.65 mmol) in dichloromethane (10 ml), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide HCl (1.52 g, 7.93 mmol) was added at 273 K. Reaction mixture was stirred at room temperature for 3 h. After the completion of the reaction, the reaction mixture was poured to ice cold water and the layers were separated. Organic layer was washed with 10% aq.NaHCO 3 solution (10 ml), brine (10 ml), dried over anhydrous Na 2 SO 4 , filtered and concentrated under vacuum to obtain the crude product which was triturated with ethanol and filtered to afford 1.62 g of the title compound (I) as a white solid in 84% yield. Single crystals were grown from ethanol by the slow evaporation method (m.p. 381-382 K).

Refinement
Atom H3N was located in a difference Fourier map and refined isotropically. All of the remaining H atoms were placed in their calculated positions and then refined using the riding model with C-H = 0.93 Å (CH), 0.97 Å (CH 2 ) or 0.96 Å (CH 3 ).
The U iso (H) values were set to 1.2 (CH, CH 2 ) or 1.5 CH 3 ) times U eq of the parent atom.

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 > 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.