2-Amino-6-methyl-5-{5-[(naphthalen-2-yloxy)methyl]-1,3,4-oxadiazol-2-ylsulfanyl}-4-(3-nitrophenyl)pyridine-3-carbonitrile

The asymmetric unit of the title compound, C26H18N6O4S, contains two independent molecules (A and B). The dihedral angles between the oxadiazole ring and naphthalene ring system are 42.59 (14) and 6.88 (14) Å in molecules A and B, respectively. The dihedral angles between the pyridine and benzene rings in A and B are 65.53 (13 )and 87.67 (13) Å, respectively. In the crystal, molecules A and B are linked through a pair of N—H⋯N hydrogen bonds involving one -NH2 group H atom and second pair of N—H⋯N hydrogen bonds involving the other -NH2 group H atom, forming an –ABAB– ribbon along [100] containing R 2 2(8) and R 2 2(12) ring motifs. These ribbons are further connected by weak C—H⋯N, C—H⋯O and C—H⋯π interactions, resulting in a three-dimensional network. The crystal studied was a non-merohedral twin with refined components 0.906 (1):0.094 (1).

The asymmetric unit of the title compound, C 26 H 18 N 6 O 4 S, contains two independent molecules (A and B). The dihedral angles between the oxadiazole ring and naphthalene ring system are 42.59 (14) and 6.88 (14) Å in molecules A and B, respectively. The dihedral angles between the pyridine and benzene rings in A and B are 65.53 (13 )and 87.67 (13) Å , respectively. In the crystal, molecules A and B are linked through a pair of N-HÁ Á ÁN hydrogen bonds involving one -NH 2 group H atom and second pair of N-HÁ Á ÁN hydrogen bonds involving the other -NH 2 group H atom, forming an -ABAB-ribbon along [100] containing R 2 2 (8) and R 2 2 (12) ring motifs. These ribbons are further connected by weak C-HÁ Á ÁN, C-HÁ Á ÁO and C-HÁ Á Á interactions, resulting in a three-dimensional network. The crystal studied was a nonmerohedral twin with refined components 0.906 (1):0.094 (1).
In the crystal structure ( Fig. 2), molecule A is paired with molecule B via an N4-H···N3 ii hydrogen bonds (symmetry code in Table 1), involving the 4-amino group and the pyridine N1 atom and it is paired with another molecule of B through a pair N4-H···N5 i hydrogen bonds (symmetry code in Table 1), involving the 4-amino group and cyano N5 atom, forming R 2 2 (8) and R 2 2 (12) (Bernstein et al., 1995) ring motifs. These hydrogen-bonded ABAB pairs lead to a extended ribbon structure. Theese ribbon are linked by weak C-H···N, C-H···O hydrogen bonds, resulting in a threedimensional network. The crystal structure is further stabilized by C-H···π interactions (Table 1).

Figure 1
The asymmetric unit of the title compound with 50% probability displacement ellipsoids.

Figure 2
The crystal packing of the title compound. The H atoms not involved in the intermolecular interactions (dashed lines) have been omitted for clarity.

2-Amino-6-methyl-5-{5-[(naphthalen-2-yloxy)methyl]-1,3,4-oxadiazol-2-ylsulfanyl}-4-(3-nitrophenyl)pyridine-3carbonitrile
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 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.