1-Methyl-1H-2,1-benzothia­zin-4(3H)-one 2,2-dioxide

M Nawaz Tahir; Muhammad Shafiq; Islam Ullah Khan; Waseeq Ahmad Siddiqui; Muhammad Nadeem Arshad

doi:10.1107/S1600536808003498

. 2008 Feb 6;64(Pt 3):o557. doi: 10.1107/S1600536808003498

1-Methyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide

M Nawaz Tahir ^a,^*, Muhammad Shafiq ^b, Islam Ullah Khan ^b, Waseeq Ahmad Siddiqui ^c, Muhammad Nadeem Arshad ^b

PMCID: PMC2960778 PMID: 21201900

Abstract

In the crystal structure of the title compound, C₉H₉NO₃S, there is distorted tetrahedral geometry around the S atom. The sulfonyl group is almost normal to the benzene ring, while the carbonyl O atom and methyl C atom are on opposite sides of this ring. The heterocyclic ring adopts a half-boat conformation with the S atom out of the plane. The molecules are dimerized by hydrogen bonding involving the benzene ring and the sulfonyl group. These dimers are linked to each other in the same way. There is an intramolecular hydrogen bond between a methyl C—H group and a sulfonyl O atom, and a π–π interaction between the aromatic rings of two dimers at a centroid-to-centroid distance of 3.6373 (13) Å.

Related literature

For related literature, see: Cremer & Pople (1975 ▶); Harmata et al. (2004 ▶); Lombardino (1972 ▶); Misu & Togo (2003 ▶); Shafiq et al. (2008 ▶); Siddiqui et al. (2007 ▶).

Experimental

Crystal data

C₉H₉NO₃S
M _r = 211.23
Triclinic,
a = 7.4553 (4) Å
b = 8.5437 (4) Å
c = 8.7097 (4) Å
α = 67.691 (2)°
β = 70.467 (2)°
γ = 66.327 (2)°
V = 459.09 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.33 mm⁻¹
T = 296 (2) K
0.20 × 0.15 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.952, T _max = 0.971
7205 measured reflections
1787 independent reflections
1678 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.095
S = 1.09
1678 reflections
127 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.42 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007 ▶); 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 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808003498/bq2063sup1.cif

e-64-0o557-sup1.cif^{(15.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808003498/bq2063Isup2.hkl

e-64-0o557-Isup2.hkl^{(86.2KB, 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
C2—H2⋯O1ⁱ	0.93	2.58	3.432 (2)	152
C4—H4⋯O2ⁱⁱ	0.93	2.46	3.238 (3)	142
C9—H9A⋯O2	0.96	2.31	2.830 (3)	113

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

Acknowledgments

The authors acknowledge the Higher Education Commission, Islamabad, Pakistan, and Bana International, Karachi, Pakistan, for funding the purchase of the diffractometer and for technical support, respectively.

supplementary crystallographic information

Comment

Benzothiazines belong to an important heterocyclic class of compounds which find a number of applications in medicinal chemistry. Derivatives of 2,1-benzothiazines were reported to possess potent biological activities such as lipoxygenase inhibition and are used as drugs for heart diseases (Misu, & Togo, 2003). These are used as intermediate precursors for the preparation of drugs used for curing Tuberculosis (Harmata et al., 2004). The importance of 2,1-benzothiazine derivatives in medicinal chemistry has brought enormous attention to their synthesis. Herein, we report the crystal structure of the title compound.

The structure determination of the title compound (I) is in continuation to our research on derivatives of 2,1 benzothiazine (Shafiq et al., 2008). The structural isomer (II), 2-methyl-2H-1,2-benzothiazin-4(3H)one 1,1-dioxide of (I) has been reported (Siddiqui et al., 2007).

In the title compound the bond distances S1—N1 [1.6429 (13) Å] and S1—C8 [1.7514 (17) Å], have been significantly changed in comparison to 1.629 (3) Å and 1.760 (4) Å respectively as reported in (II). The change in bond angles around S is large enough which is evident from the range [99.47 (8)°-118.32 (8)°] in (I), as compared to (II) [103.05 (16)°- 118.66 (16)°]. All the atoms in heterocyclic thiazine as well as C-atoms of phenyl ring are nearly planer except that of S1. The S1 is displaced by 0.7834 (15) Å from the plane (a) defined by (C1 to C8, N1) and C-atom of methyl group is at a distance of 0.340 (3) Å from it. Thus the atoms of the two rings form a long half boat confirmation. The plane (b) defined by the atoms (O1,S1,O2) makes a dihedral angle of 89.81 (6)° to the plane (a) and hence these two planes are almost normal to each other. The O1-atom is at longest distance of -2.1912 (16) Å from plane (a). In the asymmetric unit there is an intramolecular H-bond as given in Table 2. The confirmation of the hetrocyclic ring in terms of the puckering parameters (Cremer & Pople, 1975) is described by; Q = 0.5767 (14) Å, θ = 54.98 (16)° and φ = 359.7 (2)°. The title compound is basically dimerized by H-bonding through C2—H2···O1ⁱ (i = -x, -y + 2, -z + 1) as shown in Fig 2. It is interesting that the ring formed in dimer is of twelve bonds to which the methyl groups adopt cis, trans position. The dimers are linked to each other by symmetry code ii = x, y - 1, z + 1. The closest interaction [3.283 (2) Å] occurs between O1···O1ⁱⁱⁱ (symmetry code: iii = -x, -y + 2, -z), other than atoms involved in intermolecular H-bond. There is no X—H···Cg bond, however there exist a π-π interaction between the aromatic rings of two dimers at a distance of 3.6373 (13) Å by the symmetry operation 1 - x, 1 - y, 1 - z.

Experimental

The title compound (I) was synthesized using the reported procedure (Lombardino, 1972) and crystals were grown by slow evaporation from a solution of CH₃OH at 298 K.