2013. 54, 2
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UDC 541.6:547.12:546.17:546.21
4-HYDROXY-2H-1,2-BENZOTHIAZINE-3-CARBOHYDRAZIDE 1,1-DIOXIDE-OXALOHYDRAZIDE (1:1):
X-RAY STRUCTURE AND DFT CALCULATIONS
M.N. Arshad1, O. ahin2, M. Zia-ur-Rehman3, I.U. Khan4 ,
A.M. Asiri1, H.M. Rafique 5
1Department of Chemistry & Center of Excellence for Advanced Materials Research (CEAMR) Faculty of Science,
King Abdulaziz University, Jeddah, Saudi Arabia
2Scientific and Technological Research Application and Research Center, Sinop University, Sinop, Turkey
E-mail: onurs@omu.edu.tr
sity of the Punjab, Lahore, Pakistan
Received November, 18, 2011
3Applied Chemistry Research Center, PCSIR, Laboratories Complex Ferozpur Road, Lahore, Pakistan
4Materials Chemistry Laboratory, Department of Chemistry, GC University, Lahore, Pakistan
5X-ray Diffraction and Crystallography Laboratory, Department of Physics, School of Physical Sciences, UniverRevised
— June, 2, 2012
The title compound, 4-hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide
(1:1), is determined using X-ray diffraction techniques and the molecular structure is
also optimized at the B3LYP/6-31G(d,p) level using density functional theory (DFT). The
asymmetric unit consists of four independent molecules. The oxalohydrazide molecules have
the centre of symmetry at the mid-point of the central C—C bond. Each thiazine ring adopts a
half-chair conformation. Intermolecular C—H…O, N—H…O and N—H…N hydrogen bonds
produce 2
R2 (10),
2
R2 (13),
3
R3 (12) and 3
R3 (15) rings, which lead to one-dimensional polymeric
chains. An extensive three-dimensional supramolecular network of N—H…N, N—H…O,
C—H…O and O—H…O hydrogen bonds is responsible for crystal structure stabilization.
Keywords: X-ray diffraction analysis, benzothiazine, oxalohydrazide, DFT, Mulliken
atomic charge, molecular electrostatic potential.
Synthesis and structural characterization of carbohydrazides and their derivatives is much focused
in the recent literature due to their applications in biochemistry as well as in materials synthesis via
complexation [ 1, 2 ]. They are well known for their anti-viral [ 3 ], anti-tuberculoses [ 4 ], anti-fungal
[ 5 ], bacteriostatic [ 6 ], insecticidal [ 7 ] and anti-parasitic [ 8 ] activities. As part of a research program
regarding the synthesis of new derivatives of benzothiazine 1,1-dioxides [ 9, 10 ], the synthesis and
crystal structure of 4-hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide
(1:1) is reported here.
The title compound was synthesized from commercially available saccharin, which was converted
to methyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide by a reported procedure
[ 11 ] and was subsequently subjected to hydrazinolysis in methanol along with equimolar dimethyl
oxalate. It was interesting to note that dimethyl oxalate did not react with benzothiazine hydrazide under
these reaction conditions, but reacted with hydrazine and co-crystallized with the product oxalohydrazide.
Experimental.
Synthesis. A mixture of methyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate
1,1-dioxide (2.00 g, 7.84 mmol), hydrazine hydrate (1.57 g, 31.36 mmol) and dimethyl oxalate
(1.02 g, 39.2 mmol) was stirred in ethanol (30 ml) for half an hour. On completion of reaction, as indi©
Arshad M.N., ahin O., Zia-ur-Rehman M., Khan I.U., Asiri A.M., Rafique H.M., 2013
. 375 – 380
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