(Z)-3-(2,4-Dichloro­benz­yl)-1,5-benzo­thia­zepin-4(5H)-one

S Murugavel; N Manikandan; R Selvakumar; M Bakthadoss

doi:10.1107/S1600536813007435

. 2013 Mar 23;69(Pt 4):o564. doi: 10.1107/S1600536813007435

(Z)-3-(2,4-Dichlorobenzyl)-1,5-benzothiazepin-4(5H)-one

S Murugavel ^a,^*, N Manikandan ^b, R Selvakumar ^c, M Bakthadoss ^c,^‡

PMCID: PMC3629614 PMID: 23634101

Abstract

In the title compound, C₁₆H₁₁Cl₂NOS, the seven-membered thiazepine ring adopts a distorted twist-boat conformation. The dihedral angle between the mean plane of the benzothiazepine ring system and the benzene ring is 78.6 (1)°. The molecular conformation is stabilized by a weak intramolecular C—H⋯Cl hydrogen bond, which generates an S(5) ring motif. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related molecules into dimers, generating R ₂ ²(8) ring motifs. The crystal packing also features alternating π–π interactions between benzothiazepine benzene rings [inter-centroid distance = 3.740 (3) Å] and dichlorobenzene rings [inter-centroid distance = 3.882 (3) Å] to consolidate a three-dimensional architecture.

Related literature

For background to the biology and related structures of thiazepin derivatives, see: Bakthadoss et al. (2013 ▶). For ring-puckering parameters, see: Cremer & Pople (1975 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). graphic file with name e-69-0o564-scheme1.jpg

Experimental

Crystal data

C₁₆H₁₁Cl₂NOS
M _r = 336.22
Triclinic,
a = 7.879 (5) Å
b = 9.667 (5) Å
c = 9.979 (5) Å
α = 89.052 (5)°
β = 78.161 (4)°
γ = 83.647 (5)°
V = 739.3 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.58 mm⁻¹
T = 293 K
0.24 × 0.21 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.871, T _max = 0.917
18415 measured reflections
5225 independent reflections
4013 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.123
S = 1.04
5225 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.55 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and 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, 2012 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Click here for additional data file.^{(23.7KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813007435/tk5208sup1.cif

e-69-0o564-sup1.cif^{(23.7KB, cif)}

Click here for additional data file.^{(250.7KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813007435/tk5208Isup2.hkl

e-69-0o564-Isup2.hkl^{(250.7KB, hkl)}

Click here for additional data file.^{(5.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813007435/tk5208Isup3.cml

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
C10—H10B⋯Cl1	0.97	2.64	3.103 (3)	109
N1—H1A⋯O1ⁱ	0.86	2.10	2.873 (2)	149

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Dr Babu Vargheese, SAIF, IIT, Madras, India, for the data collection.

supplementary crystallographic information

Comment

The background to the biology and related structures of thiazepin derivatives, has been described recently (Bakthadoss et al., 2013). In view of this biological importance, the crystal structure of the title compound has been carried out and the results are presented here.

Fig. 1. shows a displacement ellipsoid plot of (I), with the atom numbering scheme. The seven membered thiazepine ring (N1/S1/C1/C2/C7/C8/C9) adopts distorted twist-boat conformation as indicated by puckering parameters (Cremer & Pople, 1975): QT = 0.8962 (12) Å, φ₂ = 353.2 (1)° and φ₃ = 358.9 (3)°. The atom O1 deviates by 0.667 (1) Å from the least-squares plane of the thiazepin ring. The dihedral angle between the benzothiazepin ring system and the benzene ring is 78.6 (1)°. The atoms Cl1 and Cl2 deviate by 0.075 (1) and -0.006 (1) Å, respectively, from the plane of the attached benzene ring (C11–C16). The sum of angles at N1 atom of the thiazepin ring (360.0°) is in accordance with sp² hybridization. The geometric parameters of the title molecule agree well with those reported for similar structures (Bakthadoss et al., 2013).

The molecular conformation is stabilized by a weak intramolecular C10—H10B···Cl1 hydrogen bond, which generates an S(5) ring motif (Bernstein et al., 1995). In the crystal packing, molecules are linked by N1—H1A···O1 hydrogen bonds into cyclic centrosymmetric R₂²(8) dimers (Fig. 2 and Table 1). The crystal packing is further stabilized by alternating π–π interactions with Cg1···Cg1ⁱⁱ = 3.740 (3) Å (symmetry code: (ii) = 2-x, -y, 2-z) and Cg2···Cg2ⁱⁱⁱ = 3.882 (3) Å (symmetry code: (iii) = 1-x, 1-y, 1-z) forming supramolecular stacks along the a axis (Fig. 3; Cg1 and Cg2 are the centroids of the C2–C7 and C11–C16 benzene rings, respectively).

Experimental

A mixture of (Z)-methyl 2-(bromomethyl)-3-(2,4-dichlorophenyl)acrylate 2 mmol) and o-aminothiophenol (2 mmol) in the presence of potassium tert-butoxide (4.8 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 20 ml). The organic layer was washed with brine (2 x 20 ml) and dried over anhydrous sodium sulfate. The organic layer was concentrated, which successfully provide the crude final product ((Z)-3-(2,4dichlorobenzyl)benzo[b][1,4]thiazepin-4(5H)-one). The final product was purified by column chromatography on silica gel to afford the title compound in good yield (42%). Single crystals suitable for X-ray diffraction were obtained by slow evaporation of its ethylacetate solution at room temperature.