4-Methyl-3-phenyl-2,4-dihydro­pyrazolo­[4,3-c][1,2]benzothia­zine 5,5-dioxide

Sana Aslam; Hamid Latif Siddiqui; Matloob Ahmad; Muhammad Zia-ur-Rehman; Masood Parvez

doi:10.1107/S1600536812033284

. 2012 Aug 1;68(Pt 9):o2615–o2616. doi: 10.1107/S1600536812033284

4-Methyl-3-phenyl-2,4-dihydropyrazolo[4,3-c][1,2]benzothiazine 5,5-dioxide¹

Sana Aslam ^a, Hamid Latif Siddiqui ^a, Matloob Ahmad ^b,^*, Muhammad Zia-ur-Rehman ^c, Masood Parvez ^d

PMCID: PMC3435645 PMID: 22969518

Abstract

In the title molecule, C₁₆H₁₃N₃O₂S, the heterocyclic thiazine ring adopts a twist chair conformation with the S atom and an adjacent C atom displaced by 0.946 (5) and 0.405 (6) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean planes of the benzene rings make dihedral angles of 16.61 (10) and 15.32 (10)° with the mean plane of the pyrazole ring. The molecular structure is consolidated by intramolecular C—H⋯N interactions and the crystal packing is stabilized by N—H⋯O and C—H⋯N hydrogen bonds. The crystal studied was an inversion twin with the refined ratio of the twin components being 0.53 (11):0.47 (11).

Related literature

For the biological activity of related compounds, see: Turck et al. (1996 ▶); Silverstein et al. (2000 ▶); Lombardino et al. (1973 ▶); Zinnes et al. (1973 ▶); Ahmad et al. (2010a ▶,b ▶). For related structures, see: Siddiqui et al. (2008 ▶, 2009 ▶).

Experimental

Crystal data

C₁₆H₁₃N₃O₂S
M _r = 311.35
Orthorhombic,
a = 12.1028 (5) Å
b = 16.3934 (7) Å
c = 7.0962 (3) Å
V = 1407.93 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 295 K
0.20 × 0.10 × 0.06 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1997 ▶) T _min = 0.953, T _max = 0.986
8451 measured reflections
3037 independent reflections
2798 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.112
S = 1.08
3037 reflections
201 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.24 e Å⁻³
Absolute structure: inversion twin; used 1306 unmerged Friedel pairs (Flack, 1983 ▶)
Flack parameter: 0.53 (11)

Data collection: COLLECT (Nonius, 1999 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶); data reduction: SCALEPACK (Otwinowski & Minor, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812033284/yk2066sup1.cif

e-68-o2615-sup1.cif^{(24.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812033284/yk2066Isup2.hkl

e-68-o2615-Isup2.hkl^{(146KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812033284/yk2066Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯O2ⁱ	0.86	2.12	2.912 (3)	152
C3—H3⋯N3ⁱⁱ	0.93	2.56	3.429 (4)	155
C16—H16⋯N1	0.93	2.62	3.263 (4)	127

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors are grateful to the Higher Education Commission, Pakistan, and Institute of Chemistry, University of the Punjab, Lahore, Pakistan, for financial support.

supplementary crystallographic information

Comment

Among the broad class of heterocyclic compounds, pyrazole and benzothiazine nuclei are well known for their biological activity potential. Oxicam drugs are benzothiazine based potent anti-inflammatory and analgesic drugs (Turck et al. 1996; Lombardino et al., 1973; Zinnes et al., 1973), whereas celecoxib, an anti-inflammatory drug and selective inhibitor of cox-2 enzyme, contains pyrazole fragment (Silverstein et al., 2000). Keeping in view these facts and figures, we have prepared some pyrazolobenzothiazines which contain both of these medicinally important heterocycles fused with eachother (Ahmad et al., 2010a & b). We report here the crystal structure of the title compound.

The bond distances and angles in the title compound (Fig. 1) agree very well with the corresponding bond distances and angles observed in closely related structures (Siddiqui et al., 2008; 2009). The heterocyclic thiazine ring adopts a twist chair conformation with atoms S1 and C1 displaced by 0.946 (5) and 0.405 (6) Å, respectively, on the same side from the mean plane formed by the remaining ring atoms (N1/C6–C8). The mean planes of the benzene rings C1–C6 and C11–C16 make dihedral angles 16.61 (10) and 15.32 (10)°, respectively, with the mean-plane of the pyrazole ring (N2/N3/C7/C8/C10).

The molecular structure of the title compound is consolidated by intramolecular interactions C10—H10C···O1 and C16—H16···N1. The crystal structure is stabilized by intermolecular hydrogen bonding interactions N2—H2N···O2 and C3—H3···N3 (Fig. 2 and Table 1).

Experimental

A mixture of 3-benzoyl-4-hydroxy-2-methyl-2H-1,2-benzothiazine 1,1-dioxide (5.0 g, 0.020 mol), hydrazine hydrate (5 ml) and ethanol (30 ml) was refluxed for 5 h followed by the removal of solvent under vacuum. The residue obtained was washed with cold water to get the title compound as a white crystalline product. Transparent crystals suitable for X-ray crystallographic studies were grown from a CHCl₃ solution at room temperature by slow evaporation.