4-(2-{[4-Amino-6-(4-nitrobenzyl)-5-oxo-4,5-dihydro-1,2,4-triazin-3-yl]sulfanyl}acetyl)-3-phenylsydnone

In the crystal, C20H15N7O6S, the dihedral angle between the oxadiazole and triazine rings is 86.94 (7)°. The oxadiazole ring makes a dihedral angle of 52.96 (8)° with the phenyl ring, while the triazine ring makes a dihedral angle of 82.08 (7)° with the benzene ring. In the structure, molecules are linked by a pair of N—H⋯O hydrogen bonds, forming an inversion dimer. The dimers are further stacked along the a axis via N—H⋯N hydrogen bonds. Weak intermolecular C—H⋯O interactions are also observed.


Comment
Sydnones are mesoionic heterocyclic aromatic compounds. The study of sydnones still remains a field of interest because of their electronic structures and also because of the varied types of biological activities displayed by some of them (Rai et al., 2008). Recently sydnone derivatives were found to exhibit promising antimicrobial properties (Kalluraya et al., 2008).
Since their discovery, sydnones have shown diverse biological activities and it is thought that the meso-ionic nature of the sydnone ring promotes significant interactions with biological systems. Because of wide variety of properties displayed by sydnones ,we were prompted to synthesize a new S-substituted triazinones containing a sydnone ring.
Crystals suitable for X-ray analysis were obtained from 1:2 mixtures of DMF and ethanol by slow evaporation.

Refinement
N-bound H atoms were located in a difference Fourier map and were refined freely. The remaining H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 or 0.97 Å, and with U iso (H) = 1.2U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atom-numbering scheme. Hydrogen atoms are shown as spheres of arbitrary radius.

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.