7-(4-Chlorobenzylidene)-3-[(4-chlorophenoxy)methyl]-6-(4-nitrothiophen-2-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine

In the title compound, C22H13Cl2N5O3S2, the thiadiazine ring adopts a half-chair conformation. The benzene rings of the chlorophenoxy and chlorobenzyl groups and the thiophene ring form dihedral angles of 35.6 (1), 80.7 (1) and 14.2 (1)°, respectively, with the triazole ring. In the crystal, molecules are connected into sheets parallel to (11) by intermolecular C—H⋯N and C—H⋯Cl hydrogen bonds. In addition, π–π stacking interactions are observed between thiophene and triazole rings, and between inversion-related triazole rings [centroid–centroid distances = 3.5975 (11) and 3.4324 (11) Å].

In the title compound, C 22 H 13 Cl 2 N 5 O 3 S 2 , the thiadiazine ring adopts a half-chair conformation. The benzene rings of the chlorophenoxy and chlorobenzyl groups and the thiophene ring form dihedral angles of 35.6 (1), 80.7 (1) and 14.2 (1) , respectively, with the triazole ring. In the crystal, molecules are connected into sheets parallel to (111) by intermolecular C-HÁ Á ÁN and C-HÁ Á ÁCl hydrogen bonds. In addition,stacking interactions are observed between thiophene and triazole rings, and between inversion-related triazole rings [centroid-centroid distances = 3.5975 (11) and 3.4324 (11) Å ].

Comment
The 1,2,4-triazole nucleus has been incorporated into a wide variety of therapeutically interesting compounds. Several compounds containing 1,2,4-triazole rings are well known as drugs. For example, fluconazole is used as an antimicrobial drug (Shujuan et al., 2004), while vorozole, letrozole and anastrozole are non-steroidal drugs used for the treatment of cancer (Clemons et al., 2004) and loreclezole is used as an anticonvulsant (Johnston et al., 2002). Similarly substituted derivatives of triazole possess comprehensive bioactivities such as antimicrobial, anti-inflammatory, analgesic, antihypertensive, anticonvulsant and antiviral activities (Wei et al., 2007). In continuation of our search on the synthesis of biologically active compounds, we synthesized triazolothiadiazine from triazole.
supplementary materials sup-2 Refinement H atoms were placed in calculated positions with C-H = 0.93-0.97 Å. The U iso value of H atoms were constrained to be 1.2U eq of the carrier atom. Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Special details
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 > 2sigma(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.