Methyl 4-hydr­oxy-2H-1,2-benzothia­zine-3-carboxyl­ate 1,1-dioxide

Waseeq Ahmad Siddiqui; Saeed Ahmad; Hamid Latif Siddiqui; Mujahid Hussain Bukhari; Masood Parvez

doi:10.1107/S1600536808028584

. 2008 Sep 13;64(Pt 10):o1922. doi: 10.1107/S1600536808028584

Methyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide

Waseeq Ahmad Siddiqui ^a,^*, Saeed Ahmad ^b, Hamid Latif Siddiqui ^c, Mujahid Hussain Bukhari ^c, Masood Parvez ^d

PMCID: PMC2959412 PMID: 21201130

Abstract

The asymmetric unit of the title compound, C₁₀H₉NO₅S, contains two independent molecules. The heterocyclic thiazine rings in both molecules adopt half-chair conformations, with the S atoms in each molecule displaced by 0.455 (3) and 0.539 (3) Å and the N atoms displaced in the opposite direction by 0.214 (3) and 0.203 (3) Å, from the planes defined by the remaining ring atoms. The crystal structure is stabilized by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds involving both inter- and intramolecular interactions.

Related literature

For related literature, see: Banerjee & Sarkar (2002 ▶); Cremer & Pople, 1975 ▶; Hirai et al. (1997 ▶); Khalil et al. (2000 ▶); Myung et al. (2002 ▶); Siddiqui et al. (2006 ▶, 2008 ▶).

Experimental

Crystal data

C₁₀H₉NO₅S
M _r = 255.24
Triclinic,
a = 7.777 (2) Å
b = 10.932 (4) Å
c = 12.890 (4) Å
α = 105.569 (16)°
β = 94.588 (15)°
γ = 97.763 (16)°
V = 1038.2 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 173 (2) K
0.24 × 0.22 × 0.16 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1997 ▶) T _min = 0.927, T _max = 0.950
8716 measured reflections
4693 independent reflections
4191 reflections with (I) > 2.0 σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.088
S = 1.03
4693 reflections
321 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: HKL 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 datablocks Global, I. DOI: 10.1107/S1600536808028584/lh2686sup1.cif

e-64-o1922-sup1.cif^{(23KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808028584/lh2686Isup2.hkl

e-64-o1922-Isup2.hkl^{(225.2KB, hkl)}

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
O1—H1O⋯O4	0.81 (2)	1.86 (2)	2.600 (2)	152 (2)
N1—H1N⋯O9	0.81 (2)	2.22 (2)	2.994 (2)	162 (2)
O6—H6O⋯O9	0.81 (2)	1.91 (2)	2.634 (2)	147 (2)
N2—H2N⋯O3ⁱ	0.83 (2)	2.13 (2)	2.966 (2)	175 (2)
C4—H4⋯O8ⁱⁱ	0.95	2.36	3.259 (2)	158
C20—H20A⋯O2ⁱ	0.98	2.51	3.267 (2)	134

Open in a new tab

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

supplementary crystallographic information

Comment

The 1,2-benzothiazine-3-carboxamide 1,1-dioxide derivatives belong to oxicams, a new class of non-steroidal anti-inflammatory drugs (NSAIDs). They are important for their analgesic and anti-inflammatory activities (Hirai et al., 1997, Khalil et al., 2000; Myung et al., 2002). Besides great therapeutic potential, these are very motivating polyfunctional heterocyclic molecules by virtue of their dynamic structural features, which include different tautomeric forms and their possible polymorphism (Banerjee et al., 2002). Continuing our investigations in this important field, (Siddiqui et al., 2006, 2008), we now report the crystal structure of the title compound, (I), in this paper.

An asymmetric unit of (I) contains two independent molecules presented in Figures 1 (molecule a) and 2 (molecule b). The heterocyclic thiazine rings in both molecules adopt half-chair conformations, with atoms S1 and N1 in molecule a and atoms S2 and N2 in molecule b displaced by -0.455 (3), 0.214 (3), -0.539 (3) and 0.203 (3) Å, from the planes defined by C1/C6/C7/C8 and C11/C16/C17/C18, respectively; the puckering parameters (Cremer & Pople, 1975) are Q = 0.4365 (12) and 0.4901 (12) Å, θ = 61.8 (2) and 64.1 (2)° and φ = 19.6 (2) and 17.5 (2)°, respectively. Similar conformations of the corresponding rings have been reported in some closely related compounds (Siddiqui et al., 2008).

The structure is stabilized by classical as well as non-classical hydrogen bonding (Fig. 3). Details of the hydrogen bonding geometry have been provided in Table 1.

Experimental

The synthesis of the title compound as an important intermediate in the synthesis of oxicams has been reported (Siddiqui et al., 2006). Crystals suitable for crystallographic studies were obtained from a solution of MeOH by slow evaporation at 313 K.