4-(1H-Benzimidazol-2-ylmethyl)-2H-1,4-benzothiazin-3(4H)-one

In the title compound, C16H13N3OS, the thiomorpholine ring exists in a screw boat conformation. The angle between the benzimidazole ring system and the benzene ring fused to the thiazine ring is 67.22 (6)°. In the crystal, molecules form infinite chains along the a axis via intermolecular N—H⋯N interactions. C—H⋯π interactions also contribute to the stability of the crystal structure.

In the title compound, C 16 H 13 N 3 OS, the thiomorpholine ring exists in a screw boat conformation. The angle between the benzimidazole ring system and the benzene ring fused to the thiazine ring is 67.22 (6) . In the crystal, molecules form infinite chains along the a axis via intermolecular N-HÁ Á ÁN interactions. C-HÁ Á Á interactions also contribute to the stability of the crystal structure.

Refinement
The H atom attached to N1 was located in a difference map and refined isotropically; N1-H1N1 = 0.86 (2)

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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.