organic compounds
2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo[4,3-c][1,2]benzothiazin-2-yl)acetic acid
aInstitute of Chemistry, University of the Punjab, Lahore 54590, Pakistan, bDepartment of Chemistry, Government College University, Faisalabad 38000, Pakistan, cApplied Chemistry Research Centre, PCSIR Laboratories Complex, Lahore 54600, Pakistan, and dDepartment of Chemistry, The University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
*Correspondence e-mail: drhamidlatif@hotmail.com
In the title molecule, C13H13N3O4S, the heterocyclic thiazine ring adopts a half-chair conformation in which the S and an adjacent C atom are displaced by 0.919 (3) and 0.300 (4) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean planes of the benzene and pyrazole rings are inclined at a dihedral angle of 18.32 (12)° with respect to each other. The acetate group is oriented at 80.75 (8)° with respect to the pyrazole ring. The is stabilized by O—H⋯N and C—H⋯O hydrogen bonds, resulting in fused eight- and seven-membered rings with R22(8) and R22(7) graph-set motifs, respectively.
Related literature
For the biological activity of benzothiazine derivatives, see: Turck et al. (1996); Silverstein et al. (2000); Lombardino et al. (1973); Zinnes et al. (1973); Ahmad et al. (2010). For related structures, see: Siddiqui et al. (2008, 2009). For graph-set notation, see: Bernstein et al. (1995).
Experimental
Crystal data
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Refinement
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Data collection: COLLECT (Hooft, 1998); cell 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.
Supporting information
10.1107/S1600536812023677/pk2415sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812023677/pk2415Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812023677/pk2415Isup3.cml
3,4-Dimethyl-2,4-dihydropyrazolo[4,3-c][1,2]benzothiazine 5,5-dioxide (5.0 g, 0.020 mole) and bromoacetic acid (3.31 g, 0.024 mole) were dissolved in anhydrous dimethyl formamide (15 ml) and anhydrous potassium carbonate (6.62 g, 0.048 mole) was added to it in small portions. The resulting reaction mixture was stirred for 2.5 h under a nitrogen atmosphere. The contents of the flask were poured over ice cold 10% HCl. Transparent crystals were grown from an aqueous solution, and were used for X-ray crystallographic studies.
All H atoms were positioned geometrically and refined using a riding model, with O—H = 0.84 Å and C—H = 0.95, 0.98 and 0.99 Å, for aryl, methyl and methylene H-atoms, respectively. The Uiso(H) were included at 1.5Ueq(O) or 1.2Ueq(C).
Data collection: COLLECT (Hooft, 1998); cell
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 (Sheldrick, 2008).C13H13N3O4S | F(000) = 640 |
Mr = 307.32 | Dx = 1.527 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 1947 reflections |
a = 10.495 (4) Å | θ = 1.0–27.5° |
b = 8.415 (2) Å | µ = 0.26 mm−1 |
c = 15.136 (6) Å | T = 173 K |
β = 91.034 (19)° | Block, colorless |
V = 1336.5 (8) Å3 | 0.14 × 0.12 × 0.10 mm |
Z = 4 |
Nonius KappaCCD diffractometer | 3048 independent reflections |
Radiation source: fine-focus sealed tube | 2196 reflections with I > σ(I) |
Graphite monochromator | Rint = 0.033 |
ω and ϕ scans | θmax = 27.5°, θmin = 4.1° |
Absorption correction: multi-scan (SORTAV; Blessing, 1997) | h = −13→13 |
Tmin = 0.964, Tmax = 0.974 | k = −10→10 |
5770 measured reflections | l = −19→19 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.042 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.047P)2 + 0.650P] where P = (Fo2 + 2Fc2)/3 |
3048 reflections | (Δ/σ)max < 0.001 |
193 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.35 e Å−3 |
C13H13N3O4S | V = 1336.5 (8) Å3 |
Mr = 307.32 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 10.495 (4) Å | µ = 0.26 mm−1 |
b = 8.415 (2) Å | T = 173 K |
c = 15.136 (6) Å | 0.14 × 0.12 × 0.10 mm |
β = 91.034 (19)° |
Nonius KappaCCD diffractometer | 3048 independent reflections |
Absorption correction: multi-scan (SORTAV; Blessing, 1997) | 2196 reflections with I > σ(I) |
Tmin = 0.964, Tmax = 0.974 | Rint = 0.033 |
5770 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.25 e Å−3 |
3048 reflections | Δρmin = −0.35 e Å−3 |
193 parameters |
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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.20345 (5) | 0.30572 (6) | 0.10421 (3) | 0.03013 (16) | |
O1 | 0.07080 (15) | 0.28041 (19) | 0.08552 (10) | 0.0419 (4) | |
O2 | 0.29133 (16) | 0.17922 (17) | 0.08858 (10) | 0.0392 (4) | |
O3 | 0.65265 (14) | 0.19936 (17) | 0.27745 (10) | 0.0328 (4) | |
O4 | 0.82589 (14) | 0.30151 (18) | 0.34514 (10) | 0.0344 (4) | |
H4O | 0.8579 | 0.2128 | 0.3330 | 0.052* | |
N1 | 0.21936 (16) | 0.35819 (19) | 0.20921 (10) | 0.0258 (4) | |
N2 | 0.52959 (16) | 0.54568 (18) | 0.19902 (10) | 0.0246 (4) | |
N3 | 0.52853 (15) | 0.48638 (19) | 0.28304 (10) | 0.0234 (4) | |
C1 | 0.25731 (19) | 0.4733 (2) | 0.04545 (12) | 0.0261 (4) | |
C2 | 0.1949 (2) | 0.5191 (2) | −0.03202 (13) | 0.0306 (5) | |
H2 | 0.1192 | 0.4665 | −0.0512 | 0.037* | |
C3 | 0.2448 (2) | 0.6428 (3) | −0.08089 (13) | 0.0344 (5) | |
H3 | 0.2035 | 0.6747 | −0.1344 | 0.041* | |
C4 | 0.3543 (2) | 0.7200 (3) | −0.05234 (13) | 0.0332 (5) | |
H4 | 0.3889 | 0.8027 | −0.0873 | 0.040* | |
C5 | 0.4142 (2) | 0.6782 (2) | 0.02673 (13) | 0.0284 (5) | |
H5 | 0.4883 | 0.7338 | 0.0464 | 0.034* | |
C6 | 0.36539 (19) | 0.5540 (2) | 0.07754 (12) | 0.0250 (4) | |
C7 | 0.41474 (19) | 0.5083 (2) | 0.16483 (12) | 0.0238 (4) | |
C8 | 0.34399 (18) | 0.4208 (2) | 0.22614 (12) | 0.0225 (4) | |
C9 | 0.1114 (2) | 0.4429 (3) | 0.25009 (15) | 0.0353 (5) | |
H9A | 0.1249 | 0.4473 | 0.3143 | 0.042* | |
H9B | 0.0318 | 0.3862 | 0.2366 | 0.042* | |
H9C | 0.1061 | 0.5512 | 0.2264 | 0.042* | |
C10 | 0.41904 (18) | 0.4087 (2) | 0.30145 (12) | 0.0228 (4) | |
C11 | 0.3945 (2) | 0.3369 (2) | 0.38914 (13) | 0.0302 (5) | |
H11A | 0.3108 | 0.2851 | 0.3879 | 0.036* | |
H11B | 0.3958 | 0.4202 | 0.4344 | 0.036* | |
H11C | 0.4605 | 0.2580 | 0.4030 | 0.036* | |
C12 | 0.64872 (19) | 0.4694 (2) | 0.33106 (13) | 0.0262 (4) | |
H12A | 0.6344 | 0.4829 | 0.3951 | 0.031* | |
H12B | 0.7084 | 0.5533 | 0.3121 | 0.031* | |
C13 | 0.70744 (18) | 0.3072 (2) | 0.31454 (12) | 0.0226 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0322 (3) | 0.0236 (3) | 0.0343 (3) | −0.0031 (2) | −0.0082 (2) | 0.0006 (2) |
O1 | 0.0357 (9) | 0.0422 (9) | 0.0471 (9) | −0.0137 (7) | −0.0147 (7) | 0.0061 (7) |
O2 | 0.0499 (11) | 0.0234 (8) | 0.0441 (9) | 0.0048 (7) | −0.0049 (7) | −0.0029 (6) |
O3 | 0.0285 (8) | 0.0275 (7) | 0.0423 (8) | 0.0018 (6) | −0.0052 (7) | −0.0026 (7) |
O4 | 0.0251 (8) | 0.0325 (8) | 0.0454 (9) | 0.0070 (6) | −0.0072 (7) | −0.0052 (7) |
N1 | 0.0196 (9) | 0.0262 (8) | 0.0315 (9) | −0.0028 (7) | −0.0037 (7) | 0.0022 (7) |
N2 | 0.0240 (9) | 0.0232 (8) | 0.0268 (8) | 0.0009 (7) | 0.0010 (7) | 0.0018 (7) |
N3 | 0.0199 (9) | 0.0239 (8) | 0.0264 (8) | 0.0003 (7) | −0.0019 (6) | 0.0023 (7) |
C1 | 0.0269 (12) | 0.0238 (10) | 0.0275 (10) | 0.0046 (8) | 0.0004 (8) | −0.0016 (8) |
C2 | 0.0326 (13) | 0.0298 (11) | 0.0292 (10) | 0.0041 (9) | −0.0047 (9) | −0.0052 (9) |
C3 | 0.0406 (14) | 0.0390 (12) | 0.0234 (9) | 0.0077 (10) | −0.0018 (9) | 0.0026 (9) |
C4 | 0.0337 (13) | 0.0371 (12) | 0.0291 (10) | 0.0030 (10) | 0.0057 (9) | 0.0067 (9) |
C5 | 0.0238 (11) | 0.0310 (11) | 0.0304 (10) | 0.0012 (9) | 0.0030 (8) | 0.0019 (9) |
C6 | 0.0226 (11) | 0.0247 (10) | 0.0277 (9) | 0.0055 (8) | 0.0010 (8) | −0.0005 (8) |
C7 | 0.0215 (11) | 0.0203 (9) | 0.0296 (10) | 0.0013 (8) | −0.0011 (8) | −0.0005 (8) |
C8 | 0.0203 (10) | 0.0195 (9) | 0.0277 (9) | 0.0005 (8) | 0.0004 (8) | 0.0009 (8) |
C9 | 0.0210 (11) | 0.0393 (12) | 0.0456 (12) | −0.0035 (9) | 0.0026 (9) | −0.0003 (10) |
C10 | 0.0204 (10) | 0.0198 (9) | 0.0284 (9) | 0.0013 (8) | 0.0006 (8) | 0.0006 (8) |
C11 | 0.0279 (12) | 0.0313 (11) | 0.0313 (10) | −0.0019 (9) | −0.0008 (9) | 0.0052 (9) |
C12 | 0.0224 (11) | 0.0262 (10) | 0.0297 (10) | −0.0013 (8) | −0.0042 (8) | −0.0009 (8) |
C13 | 0.0181 (10) | 0.0266 (10) | 0.0231 (9) | 0.0000 (8) | 0.0001 (7) | 0.0033 (8) |
S1—O2 | 1.4309 (16) | C3—H3 | 0.9500 |
S1—O1 | 1.4315 (17) | C4—C5 | 1.387 (3) |
S1—N1 | 1.6550 (18) | C4—H4 | 0.9500 |
S1—C1 | 1.765 (2) | C5—C6 | 1.401 (3) |
O3—C13 | 1.207 (2) | C5—H5 | 0.9500 |
O4—C13 | 1.320 (2) | C6—C7 | 1.462 (3) |
O4—H4O | 0.8400 | C7—C8 | 1.407 (3) |
N1—C8 | 1.429 (2) | C8—C10 | 1.378 (3) |
N1—C9 | 1.483 (3) | C9—H9A | 0.9800 |
N2—C7 | 1.341 (2) | C9—H9B | 0.9800 |
N2—N3 | 1.366 (2) | C9—H9C | 0.9800 |
N3—C10 | 1.355 (2) | C10—C11 | 1.485 (3) |
N3—C12 | 1.452 (2) | C11—H11A | 0.9800 |
C1—C2 | 1.388 (3) | C11—H11B | 0.9800 |
C1—C6 | 1.401 (3) | C11—H11C | 0.9800 |
C2—C3 | 1.385 (3) | C12—C13 | 1.520 (3) |
C2—H2 | 0.9500 | C12—H12A | 0.9900 |
C3—C4 | 1.383 (3) | C12—H12B | 0.9900 |
O2—S1—O1 | 118.95 (10) | C1—C6—C7 | 117.20 (18) |
O2—S1—N1 | 107.64 (9) | N2—C7—C8 | 110.47 (17) |
O1—S1—N1 | 108.08 (10) | N2—C7—C6 | 126.05 (17) |
O2—S1—C1 | 107.32 (10) | C8—C7—C6 | 123.45 (18) |
O1—S1—C1 | 109.78 (9) | C10—C8—C7 | 106.48 (17) |
N1—S1—C1 | 104.07 (9) | C10—C8—N1 | 128.98 (17) |
C13—O4—H4O | 109.5 | C7—C8—N1 | 124.53 (17) |
C8—N1—C9 | 116.85 (16) | N1—C9—H9A | 109.5 |
C8—N1—S1 | 110.29 (13) | N1—C9—H9B | 109.5 |
C9—N1—S1 | 117.66 (13) | H9A—C9—H9B | 109.5 |
C7—N2—N3 | 104.55 (15) | N1—C9—H9C | 109.5 |
C10—N3—N2 | 112.87 (15) | H9A—C9—H9C | 109.5 |
C10—N3—C12 | 125.58 (16) | H9B—C9—H9C | 109.5 |
N2—N3—C12 | 118.72 (15) | N3—C10—C8 | 105.57 (16) |
C2—C1—C6 | 121.69 (19) | N3—C10—C11 | 122.79 (17) |
C2—C1—S1 | 119.80 (16) | C8—C10—C11 | 131.57 (18) |
C6—C1—S1 | 118.48 (15) | C10—C11—H11A | 109.5 |
C3—C2—C1 | 118.9 (2) | C10—C11—H11B | 109.5 |
C3—C2—H2 | 120.6 | H11A—C11—H11B | 109.5 |
C1—C2—H2 | 120.6 | C10—C11—H11C | 109.5 |
C4—C3—C2 | 120.44 (19) | H11A—C11—H11C | 109.5 |
C4—C3—H3 | 119.8 | H11B—C11—H11C | 109.5 |
C2—C3—H3 | 119.8 | N3—C12—C13 | 110.94 (15) |
C3—C4—C5 | 120.8 (2) | N3—C12—H12A | 109.5 |
C3—C4—H4 | 119.6 | C13—C12—H12A | 109.5 |
C5—C4—H4 | 119.6 | N3—C12—H12B | 109.5 |
C4—C5—C6 | 119.9 (2) | C13—C12—H12B | 109.5 |
C4—C5—H5 | 120.1 | H12A—C12—H12B | 108.0 |
C6—C5—H5 | 120.1 | O3—C13—O4 | 125.03 (18) |
C5—C6—C1 | 118.26 (18) | O3—C13—C12 | 124.07 (17) |
C5—C6—C7 | 124.43 (18) | O4—C13—C12 | 110.90 (16) |
O2—S1—N1—C8 | 64.00 (15) | N3—N2—C7—C6 | 176.09 (18) |
O1—S1—N1—C8 | −166.34 (12) | C5—C6—C7—N2 | −18.7 (3) |
C1—S1—N1—C8 | −49.68 (15) | C1—C6—C7—N2 | 165.16 (18) |
O2—S1—N1—C9 | −158.49 (15) | C5—C6—C7—C8 | 159.33 (19) |
O1—S1—N1—C9 | −28.84 (17) | C1—C6—C7—C8 | −16.8 (3) |
C1—S1—N1—C9 | 87.83 (16) | N2—C7—C8—C10 | 1.5 (2) |
C7—N2—N3—C10 | 2.1 (2) | C6—C7—C8—C10 | −176.80 (17) |
C7—N2—N3—C12 | 164.15 (16) | N2—C7—C8—N1 | −177.84 (17) |
O2—S1—C1—C2 | 105.04 (18) | C6—C7—C8—N1 | 3.8 (3) |
O1—S1—C1—C2 | −25.6 (2) | C9—N1—C8—C10 | 76.3 (3) |
N1—S1—C1—C2 | −141.05 (16) | S1—N1—C8—C10 | −145.81 (18) |
O2—S1—C1—C6 | −73.08 (18) | C9—N1—C8—C7 | −104.5 (2) |
O1—S1—C1—C6 | 156.31 (16) | S1—N1—C8—C7 | 33.4 (2) |
N1—S1—C1—C6 | 40.84 (18) | N2—N3—C10—C8 | −1.2 (2) |
C6—C1—C2—C3 | 3.3 (3) | C12—N3—C10—C8 | −161.78 (17) |
S1—C1—C2—C3 | −174.78 (15) | N2—N3—C10—C11 | −178.68 (17) |
C1—C2—C3—C4 | −0.6 (3) | C12—N3—C10—C11 | 20.8 (3) |
C2—C3—C4—C5 | −1.8 (3) | C7—C8—C10—N3 | −0.2 (2) |
C3—C4—C5—C6 | 1.5 (3) | N1—C8—C10—N3 | 179.14 (18) |
C4—C5—C6—C1 | 1.1 (3) | C7—C8—C10—C11 | 177.0 (2) |
C4—C5—C6—C7 | −175.00 (19) | N1—C8—C10—C11 | −3.7 (4) |
C2—C1—C6—C5 | −3.5 (3) | C10—N3—C12—C13 | 70.0 (2) |
S1—C1—C6—C5 | 174.58 (15) | N2—N3—C12—C13 | −89.5 (2) |
C2—C1—C6—C7 | 172.87 (18) | N3—C12—C13—O3 | −10.2 (3) |
S1—C1—C6—C7 | −9.0 (2) | N3—C12—C13—O4 | 168.99 (16) |
N3—N2—C7—C8 | −2.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4O···N2i | 0.84 | 1.90 | 2.724 (2) | 165 |
C9—H9A···O2ii | 0.98 | 2.59 | 3.297 (3) | 129 |
C5—H5···O4iii | 0.95 | 2.59 | 3.476 (3) | 155 |
C12—H12B···O3iii | 0.99 | 2.35 | 3.303 (3) | 160 |
C9—H9B···O1 | 0.98 | 2.49 | 2.867 (3) | 102 |
Symmetry codes: (i) −x+3/2, y−1/2, −z+1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+3/2, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C13H13N3O4S |
Mr | 307.32 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 10.495 (4), 8.415 (2), 15.136 (6) |
β (°) | 91.034 (19) |
V (Å3) | 1336.5 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.26 |
Crystal size (mm) | 0.14 × 0.12 × 0.10 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (SORTAV; Blessing, 1997) |
Tmin, Tmax | 0.964, 0.974 |
No. of measured, independent and observed [I > σ(I)] reflections | 5770, 3048, 2196 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.110, 1.03 |
No. of reflections | 3048 |
No. of parameters | 193 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.25, −0.35 |
Computer programs: COLLECT (Hooft, 1998), DENZO (Otwinowski & Minor, 1997), SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4O···N2i | 0.84 | 1.90 | 2.724 (2) | 164.5 |
C9—H9A···O2ii | 0.98 | 2.59 | 3.297 (3) | 129.3 |
C5—H5···O4iii | 0.95 | 2.59 | 3.476 (3) | 155.4 |
C12—H12B···O3iii | 0.99 | 2.35 | 3.303 (3) | 160.2 |
Symmetry codes: (i) −x+3/2, y−1/2, −z+1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+3/2, y+1/2, −z+1/2. |
Acknowledgements
The authors are grateful to the Higher Education Commission, Pakistan, and the Institute of Chemistry, University of the Punjab, Lahore, Pakistan, for financial support.
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Meloxicam and Celecoxib are well known for their selective inhibition of the cox-2 enzyme that is responsible for inflammation (Turck et al., 1996; Silverstein et al., 2000). Though a number of benzothiazine based compounds have shown anti-inflammatory and analgesic character, yet there is a huge scope for selective cox-2 inhibitors in this family of heterocyclic compounds (Lombardino et al., 1973; Zinnes et al., 1973). In continuing the pursuit of potential drugs in this category, we have fused benzothiazine and pyrazole heterocycles that are core nuclei of meoxicam and celecoxib, respectively (Ahmad et al., 2010), we have synthesized and determined the crystal structure of the title compound which is presented in this paper.
The bond distances and angles in the title compound (Fig. 1) agree very well with the corresponding bond distances and angles reported in closely related compounds (Siddiqui et al., 2008; 2009). The heterocyclic thiazine ring adopts a twist chair conformation with atoms S1 and C1 displaced by 0.919 (3) and 0.300 (4) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms (r.m.s. deviation 0.012 for N1/C6–C8 atoms). The mean-plane of the benzene ring C1–C6 makes a dihedral angle 18.32 (12)° with the mean-plane of the pyrazolyl ring (N2/N3/C7/C8/C10). The mean-plane of the acetate group (O3/O4/C12/C13) lies at 80.75 (8)° with respect to the pyrazolyl ring. The crystal structure is stabilized by intermolecular hydrogen bonding interactions (Fig. 2 and Table 1). The hydrogen bonds O4—H4O···N2 and C12—H12B···O3 result in eight membered rings with a R22(8) motif while C5—H5···O4 hydrogen bonding results in a seven membered ring with a R22(7) motif (Bernstein et al., 1995); both rings are fused together and result in chains of molecules along the b-axis in a zigzag fashion. Moreover, C9—H9A···O2 interactions link the title molecules into chains along the b-axis further consolidating the crystal packing.