2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo­[4,3-c][1,2]benzothia­zin-2-yl)-N′-(3-meth­oxy­benzyl­idene)aceto­hydrazide dimethyl­formamide hemisolvate

Matloob Ahmad; Hamid Latif Siddiqui; Manzoor Iqbal Khattak; Saeed Ahmad; Masood Parvez

doi:10.1107/S1600536810052177

. 2010 Dec 24;67(Pt 1):o216–o217. doi: 10.1107/S1600536810052177

2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo[4,3-c][1,2]benzothiazin-2-yl)-N′-(3-methoxybenzylidene)acetohydrazide dimethylformamide hemisolvate

Matloob Ahmad ^a,^b, Hamid Latif Siddiqui ^a,^*, Manzoor Iqbal Khattak ^c, Saeed Ahmad ^d, Masood Parvez ^e

PMCID: PMC3050140 PMID: 21522716

Abstract

In the title compound, C₂₁H₂₁N₅O₄S·0.5C₃H₇NO, the heterocyclic thiazine ring adopts a half-chair conformation, with the S and N atoms displaced by −0.451 (5) and 0.233 (5) Å, respectively, from the plane formed by the remaining ring atoms. The asymmetric unit contains a disordered half-molecule of solvent lying close to inversion centers. The crystal structure is stabilized by weak intermolecular N—H⋯O and C—H⋯O interactions.

Related literature

For related structures, see: Ahmad et al. (2008 ▶; 2009 ▶, 2011 ▶); Siddiqui et al. (2008 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₁H₂₁N₅O₄S·0.5C₃H₇NO
M _r = 476.04
Orthorhombic,
a = 18.3806 (5) Å
b = 8.1155 (2) Å
c = 30.4715 (5) Å
V = 4545.37 (18) Å³
Z = 8
Mo Kα radiation
μ = 0.19 mm⁻¹
T = 173 K
0.16 × 0.14 × 0.06 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1997 ▶) T _min = 0.971, T _max = 0.989
7438 measured reflections
3997 independent reflections
2747 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.125
S = 1.09
3997 reflections
328 parameters
35 restraints
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); 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 datablocks global, I. DOI: 10.1107/S1600536810052177/jh2242sup1.cif

e-67-0o216-sup1.cif^{(25.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052177/jh2242Isup2.hkl

e-67-0o216-Isup2.hkl^{(192KB, 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
N4—H4N⋯O3ⁱ	0.88	2.06	2.878 (3)	155
C14—H14⋯O5ⁱ	0.95	2.49	3.287 (10)	142
C16—H16⋯O5ⁱ	0.95	2.35	3.145 (11)	140
C21—H21C⋯O2ⁱⁱ	0.98	2.53	3.497 (5)	169

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

Acknowledgments

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

supplementary crystallographic information

Comment

In continuation to our research exploring potential biologically active derivatives of benzothiazines (Ahmad et al., 2008; 2009), we have devised the fusion of the pyrazole moiety with 1,2-benzothiazine nucleus in an attempt to synthesize novel bioactive molecules. In this paper, we report the synthesis and crystal structure of the title compound, (I).

In the title molecule (Fig. 1), the heterocyclic thiazine ring adopts a half-chair conformation, with atoms S1 and N1 displaced from the plane formed by atoms C1/C6/C7/C8 by -0.451 (5) and 0.233 (5) Å, respectively. The pertinent puckering parameters (Cremer & Pople, 1975) are: Q = 0.445 (2) Å, θ = 61.8 (4)° and φ = 20.6 (4)°. Similar conformations of the corresponding rings have been reported in some closely related molecules (Siddiqui et al., 2008; (Ahmad et al., 2011). The mean-plane formed by the atoms C1–C8/C10/N2/N3 (atoms of the three fused rings excluding S1 and N1) is quite planar (maximum deviation being 0.171 (2) Å for N2) and forms an angle of 80.19 (8)° with the side chain comprised of atoms C12–C14/O3/N4/N5 which links the phenyl ring C14–C16 with the pyrazolobenzothiazin moiety; the angle between the chain atoms and the phenyl ring is 20.3 (2)°.

The intermolecular hydrogen bonds N4—H4N···O3 and C21—H21C···O1 stabilize the crystal structure. Moreover, O5 of the solvate exhibits hydrogen bonding interactions with phenyl H14 and H16 atoms (Tab. 1 and Fig. 2).

Experimental

A mixture of 2-(3,4-dimethyl-5,5-dioxidopyrazolo[4,3-c][1,2]benzothiazin -2(4H)-yl)acetohydrazide (1.0 g, 3.12 mmol) and 3-methoxybenzaldehyde (0.42 g, 3.12 mmol) were dissolved in ethanol (50 ml) followed by the addition of 2 drops of glacial acetic acid. The mixture was subjected to reflux for 4 - 5 h. The completion of reaction was monitored with the help of thin layer chromatography (TLC). The precipitates formed were collected and washed with methanol (yield = 80%). The crystals of (I) suitable for crystallographic analysis were grown from its solution in dimethylformamide at room temperature by slow evaporation.