4-[(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]-2H-1,4-benzothiazin-3(4H)-one

In the title compound, C18H16N4OS, the six-membered heterocycle of the benzothiazine fragment exhibits a screw-boat conformation. The dihedral angles between the plane through the triazole ring and those through the fused and terminal benzene rings are 76.68 (11) and 71.0 (1)°, respectively; the benzene rings are nearly perpendicular [dihedral angle = 79.6 (1)°]. In the crystal, molecules are linked by C—H⋯N and C—H⋯O interactions, forming a three-dimensional network.

In the title compound, C 18 H 16 N 4 OS, the six-membered heterocycle of the benzothiazine fragment exhibits a screwboat conformation. The dihedral angles between the plane through the triazole ring and those through the fused and terminal benzene rings are 76.68 (11) and 71.0 (1) , respectively; the benzene rings are nearly perpendicular [dihedral angle = 79.6 (1) ]. In the crystal, molecules are linked by C-HÁ Á ÁN and C-HÁ Á ÁO interactions, forming a three-dimensional network.

Refinement
The H atoms were located in a difference map and treated as riding with C-H = 0.93 Å (aromatic) and C-H = 0.97 Å (methylene), and with U iso (H) = 1.2 U eq (C).
The molecule of the title compound is built up from two fused six-membered rings linked to a triazole ring, via the heterocyclic, which in turn is attached to benzene ring as shown in Fig. 1. The 1,4-thiazine ring adopts a screw boat conformation as indicated by the puckering amplitude Q = 0.6197 (17) Å, spherical polar angle θ = 64.42 (16)° and with φ = 329.6 (2)° (Cremer & Pople, 1975). The triazole ring (N1N2N3C8C9) makes dihedral angles of 76.68 (11) and 71.0 (1)° with the benzene fused to the 1,4-thiazine ring (C11 to C16) and the other benzene ring (C1 to C6), respectively. Moreover, the two benzene rings are nearly perpendicular as indicated by the dihedral angle between them of 79.6 (1)°.
In the crystal, the molecules are linked together by a weak intermolecular C8-H8···N2, C8-H8···N3 and C5-H5···O1 interactions, to form a three-dimensional network (see Fig. 2     where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.22 e Å −3 Δρ min = −0.33 e Å −3 Special details 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq C1 0.22144 (17