5-[(4-Fluoroanilino)methyl]-6-methyl-N-(4-methylphenyl)-2-phenylpyrimidin-4-amine

In the title compound, C25H23FN4, the pyrimidine ring makes dihedral angles of 11.3 (2), 24.5 (2) and 70.1 (2)° with the phenyl and two benzene rings, and the molecular conformation is stabilized by an intramolecular N—H⋯N hydrogen bond with an S(6) ring motif. In the crystal, a pair of weak C—H⋯F hydrogen bonds link two molecules into an inversion dimer with an R 2 2(16) motif. In the dimer, there is also an intermolecular π–π stacking interaction [centroid–centroid distance = 3.708 (4) Å] between the fluorinated benzene rings. The dimers are further linked by a C—H⋯π interaction, so forming a column along the c axis.

In the title compound, C 25 H 23 FN 4 , the pyrimidine ring makes dihedral angles of 11.3 (2), 24.5 (2) and 70.1 (2) with the phenyl and two benzene rings, and the molecular conformation is stabilized by an intramolecular N-HÁ Á ÁN hydrogen bond with an S(6) ring motif. In the crystal, a pair of weak C-HÁ Á ÁF hydrogen bonds link two molecules into an inversion dimer with an R 2 2 (16) motif. In the dimer, there is also an intermolecularstacking interaction [centroid-centroid distance = 3.708 (4) Å ] between the fluorinated benzene rings. The dimers are further linked by a C-HÁ Á Á interaction, so forming a column along the c axis.
The N-H···N hydrogen bonds involving the amine atom N5 as a donor are commonly observed in previously described structures (Cieplik et al., 2006(Cieplik et al., , 2012Cieplik, Pluta et al., 2011). However, in the structure of the title compound, atom H5 is not involved in any interactions. The crystal structure of the title compound is stabilized by weak C-H···F, C-H···π and π-π stacking interactions. The molecules are linked by a C-H···F interaction involving atom C57 as a donor and atom F5 (-x, -y + 1, -z + 2) as an acceptor. This results in the formation of an inversion dimer with an R 2 2 (16) ring motif. Between aryl rings of (4-fluorophenyl)aminomethyl groups of molecules forming the dimer there is also an aromatic π-π stacking interaction. The distance between the centroids of C51-C56 ring at (x, y, z) and (-x, -y + 1, -z + 2) is 3.708 (4) Å, and the interplanar spacing and the centroid offset are 3.429 (4) Å and 1.41 Å, respectively. Additionally, the C57-H572 group acts as a donor of C-H···π(arene) interaction to the pyrimidine N1/C2/N3/C4-C6 ring (-x, -y + 1, -z + 1). The combination of C-H···F and C-H···π interactions generates a column running along the [001] direction

Experimental
The title compound was obtained by adopting the procedure described previously by Cieplik et al. (2003). 4 g (0.0125 mmol) of 5-(chloromethyl)-6-methyl-N-(4-methylphenyl)-2-phenylpyrimidin-4-amine was dissolved in 50 ml of chloroform, and 2 g of 4-fluoroaniline was added. The reaction mixture was refluxed for 4 h with vigorous stirring, then was cooled and poured into 100 ml of water. The aqueous solution was extracted three times with chloroform (50 ml). The combined chloroform phases were dried over MgSO 4 , filtered and concentrated under vacuum. The oily residue was purified by column chromatography on silica gel (200-400 mesh) using CHCl 3 as the eluent and by crystallization from methanol to give single crystals (yield: 3.74 g, 76.0%, m.p. 423-425 K).

Refinement
The N-bonded H atoms were found in a difference Fourier map and their positions were refined with U iso (H) = 1.2U eq (N).
The remaining H atoms were treated as riding on their carrier atoms, with C-H distances in the range 0.95-0.99 Å, and with U iso (H) = 1.2U eq (C), except methyl groups where U iso (H) = 1.5U eq (C).    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.