2-Amino-6-(dimethylamino)pyridine-3,5-dicarbonitrile

The title compound, C9H9N5, is slightly twisted from planarity, with a maximum deviation of 0.0285 (13) Å from the pyridine plane for the C atom bearing the amino group. The cyano groups are on different sides of the pyridine plane, with C- and N-atom deviations of 0.072 (3)/0.124 (4) and −0.228 (4)/−0.409 (5) Å from the pyridine plane. In the crystal, N—H⋯N and C—H⋯N hydrogen bonds connect the molecules into zigzag chains running along the c axis.

The title compound, 2-amino-6-(dimethylamino)-pyridine-3,5-dicarbonitrile, is slightly twisted. The maximum deviation from the mean plane of the pyridyl ring, N1/C1-C5 (marked with asterisk) is 0.0285 (13)  Hydrogen bonding interactions are observed in the crystal lattice connecting the molecules into zigzag chains running along the c-axis. As it is expected, N-H···N interactions are shorter as the observed N4···H3(-C3) distance.

Experimental
The title compound (1) was obtained as a by-product from the reaction of 2-amino-6-chloropyridine-3,5-dicarbonitrile (1 mmol; 179 mg) with amino guanidine (1 mmol; 74 mg) in dimethylformamide. The reaction mixture was refluxed for 4 h at 426 K and then poured on cold water. A solid product was filtered off, dried and recrystallized from ethanol to afford cupric needles which were suitable for X-Ray diffraction without further recrystallization. Yield 45% and m.p. 453 K.

Refinement
The structure was solved by direct methods (SHELXS97, Sheldrick, 2008) and expanded using Fourier techniques. All non-H atoms were refined anisotropically.
C-bound H atoms are all placed at geometrical positions with C-H = 0.93 and 0.96 Å for phenyl and methyl H-atoms, respectively. C-bound phenyl hydrogen atoms are refined using a riding model with U iso (H) = 1.2U eq (C), methyl H-atoms are refined using a riding model with U iso (H) = 1.5U eq (C). N-bound H atoms were located from the difference Fourier map and were refined isotropically.

Figure 1
Molecular structure of the title compound showing thermal ellipsoids on the 50% probability level.

2-Amino-6-(dimethylamino)pyridine-3,5-dicarbonitrile
Crystal data C 9 H 9 N 5 M r = 187.21 Monoclinic, C2/c Hall symbol: -C 2yc a = 28.667 (7)  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.