N-Butyl-4-methyl-6-phenylpyrimidin-2-amine

In the title compound, C15H19N3, the pyrimidine ring is approximately planar [maximum deviation = 0.007 (1) Å] and forms a dihedral angle of 3.15 (6)° with the benzene ring. In the crystal packing, intermolecular N—H⋯N hydrogen bonds link pairs of neighbouring molecules into dimers with R 2 2(8) ring motifs. These dimers are stacked along the b axis.

In the title compound, C 15 H 19 N 3 , the pyrimidine ring is approximately planar [maximum deviation = 0.007 (1) Å ] and forms a dihedral angle of 3.15 (6) with the benzene ring. In the crystal packing, intermolecular N-HÁ Á ÁN hydrogen bonds link pairs of neighbouring molecules into dimers with R 2 2 (8) ring motifs. These dimers are stacked along the b axis.

Experimental
A mixture of S-methylisothiourea sulphate (556 mg, 2.0 mmol), potassium carbonate (345 mg, 2.5 mmol) and butylamine (292 mg, 4.0 mmol) was thoroughly mixed together and then irradiated at 450 Watt for 12 min in a microwave oven. The solid mass was washed with CHCl 3 to remove the unreacted butylamine and it was then dried. The solid residue formed was mixed with benzoylacetone (648 mg, 4.0 mmol) and again irradiated at 300 Watt for 5 min. Then it was dissolved in water and extracted with chloroform. The crude product was purified by column chromatography (silica gel, 100-200 mesh) with 15% ethyl acetate in petroleum ether as eluant. Single crystals were grown by slow evaporation of a chloroform solution.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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.