3-(2-Methyl­benzyl­idene)-2,3-dihydro-1,5-benzothia­zepin-4(5H)-one

D Sridevi; Sundari Bhaskaran; G Usha; G Murugan; M Bakthadoss

doi:10.1107/S1600536810052888

. 2011 Jan 8;67(Pt 2):o243. doi: 10.1107/S1600536810052888

3-(2-Methylbenzylidene)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one

D Sridevi ^a, Sundari Bhaskaran ^a, G Usha ^a,^*, G Murugan ^b, M Bakthadoss ^b

PMCID: PMC3051627 PMID: 21522937

Abstract

In the crystal structure of the title compound, C₁₇H₁₅NOS, the molecules form centrosymmetric dimers through pairs of N—H⋯O hydrogen bonds. The seven-membered ring adopts a distorted half-chair conformation.

Related literature

Dibenzo[c,e]thiepine derivatives exhibit chiroptical properties (Tomascovic et al., 2000 ▶) and dibenzo[b,e]thiepin-5,5-dioxide derivatives possess antihistaminic and antiallergenic activities (Rajsner et al., 1971 ▶) while benzene thiepine derivatives have been identified as effective antihistaminic compounds (Metys et al., 1965 ▶).

Experimental

Crystal data

C₁₇H₁₅NOS
M _r = 281.36
Monoclinic,
a = 19.1192 (5) Å
b = 13.0049 (3) Å
c = 14.8903 (4) Å
β = 128.591 (1)°
V = 2893.84 (13) Å³
Z = 8
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 293 K
0.22 × 0.18 × 0.18 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
13879 measured reflections
3560 independent reflections
2707 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.202
S = 0.83
3560 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810052888/bt5422sup1.cif

e-67-0o243-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052888/bt5422Isup2.hkl

e-67-0o243-Isup2.hkl^{(171.1KB, 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
N—H0⋯Oⁱ	0.86	2.01	2.8705 (18)	177

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Professor D. Velmurugan, Centre for Advanced Study in Crystallography and Biophysics, University of Madras, for providing data-collection and computing facilities.

supplementary crystallographic information

Comment

The title compound is used as an intermediate for the synthesis of dosulepin, which is an antidepressant of the tricyclic family. Dosulepin prevents reabsorbing of serotonin and noradrenaline in the brain, helps to prolong the mood lightening effect of any released noradrenaline and serotonin, thus relieving depression. The dibenzo[c,e]thiepine derivatives exhibit chiroptical properties (Tomascovic et al., 2000). Dibenzo[b,e]thiepin-5,5-dioxide derivatives possess antihistaminic and antiallergenic activities (Rajsner et al., 1971). Benzene thiepine derivatives are identified as a new type of effective antihistaminic compounds (Metys et al., 1965). Considering the wide range of biological activities of the thiepine derivatives, we determined the crystal structure of the title compound. The seven membered thiepin ring adopts a distorted half-chair conformation. The molecules form centrosymmetric dimers through N—H···O hydrogen bonds.

Experimental

A mixture of(Z)-methyl 2-(bromomethyl)-3-o-tolylacrylate (2 mmol) and o-aminothiophenol(2 mmol) in the presence of potassium tert-butoxide (2.4 mmol) in dry THF (10 ml) was stirred at room temperature for 1 h. After the completion of the reaction as indicated by TLC, the reaction mixture was concentrated and the resulting crude mass was diluted with water (20 ml) and extracted with ethyl acetate (3 x 20ml). The organic layer was washed with brine (2 x 20ml) and dried over anhydrous sodium sulfate. The organic layer was concentrated, which provided a crude mass (Z)-methyl 2-((2-aminophenylthio)methyl)-3-o-tolylacrylate. The crude product was treated with a catalytic amount of p-toluene sulphonic acid (0.4 mmol), in p-xylene (10 ml), under reflux conditions for 12 h. After the completion of the reaction as indicated by TLC, the reaction mixture was concentrated under reduced pressure and worked up as mentioned previously, which successfully provide the crude final product. The final product was purified by column chromatography on silica gel to afford the title compound in good yield (67%).