4-Methyl-6-(piperidin-1-yl)pyrimidin-2-amine

The title compound, C10H16N4, crystalizes with two molecules (A and B) in the asymmetric unit in which the dihedral angles between the piperidine and pyrimidine rings are 47.5 (1) and 10.3 (1)°. The four C atoms of the pyrimidine ring in one of the molecules are disordered over two sets of sites with occupancy factors 0.508 (11):0.492 (11). In the crystal, the A molecules are linked to one another through N—H⋯N hydrogen bonds, generating R 2 2(8) ring patterns and forming inversion dimers. These dimers are further connected on either side to a B molecule through pairs of N—H⋯N hydrogen bonds, resulting in a tetrameric unit.

The title compound, C 10 H 16 N 4 , crystalizes with two molecules (A and B) in the asymmetric unit in which the dihedral angles between the piperidine and pyrimidine rings are 47.5 (1) and 10.3 (1) . The four C atoms of the pyrimidine ring in one of the molecules are disordered over two sets of sites with occupancy factors 0.508 (11):0.492 (11). In the crystal, the A molecules are linked to one another through N-HÁ Á ÁN hydrogen bonds, generating R 2 2 (8) ring patterns and forming inversion dimers. These dimers are further connected on either side to a B molecule through pairs of N-HÁ Á ÁN hydrogen bonds, resulting in a tetrameric unit.
In the crystal structure, the molecules are linked to one another through N-H···N hydrogen bonds generating R 2 2 (8) ring patterns (Bernstein et al., 1995) forming inversion related dimers. These dimers are further connected to one another through a second N-H···N hydrogen bonds resulting in a tetrameric unit.

Refinement
The H atoms bound to carbon were positioned with idealized geometry using a riding model with d(C-H) = 0.93-0.97 Å.
All C-H atoms were refined with isotropic displacement parameters set to 1.2-1.5 U eq (C). N-H atoms were located in a difference Fourier map and refined freely. The C16, C17, C19 and C20 carbon atoms of a pyrimidine ring in one of the molecules were disordered over two sites and refined with site occupancy factors 0.508 (11):0.492 (11).   Crystal packing of the title compound with hydrogen bonds drawn as dashed lines.

4-Methyl-6-(piperidin-1-yl)pyrimidin-2-amine
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.    (2) 3.210 (2) 162.1 (17) Symmetry code: (i) −x+1, −y+2, −z.