4-(Thiophen-2-yl)-2-[4-(trifluoromethyl)phenyl]-2,3-dihydro-1,5-benzothiazepine

In the title compound, C20H14F3NS2, the seven-membered thiazepine ring adopts a slightly distorted twist–boat conformation. The mean plane of the five-membered thiophene ring fused to the thiazepine ring is twisted by 32.3 (3) and 55.6 (4)° from the benzene and phenyl rings, respectively. In the crystal, inversion dimers linked by pairs of weak C—H⋯N interactions are observed.

In the title compound, C 20 H 14 F 3 NS 2 , the seven-membered thiazepine ring adopts a slightly distorted twist-boat conformation. The mean plane of the five-membered thiophene ring fused to the thiazepine ring is twisted by 32.3 (3) and 55.6 (4) from the benzene and phenyl rings, respectively. In the crystal, inversion dimers linked by pairs of weak C-HÁ Á ÁN interactions are observed.

Comment
1,4-Thiazepine is a privileged structure because of its presence in a number of pharmacologically important compounds.
1, 4-thiazepine moieties represent an important class of heterocyclic compounds with diverse potential and pharmacological activities. They are used as a calcium channel blockers, HIV-1 integrase and reverse transcriptase inhibitors, antitumor, antiplatelet and antidepressant agents (Zeng et al., 2010). Compounds containing the 1, 4-thiazepine moiety are important targets in synthetic and medicinal chemistry because this fragment is a key motif in a wide number of natural and synthetic biologically active agents (Skiles et al., 1986).
In the title compound, (I), the thiazepine ring adopts a slightly distorted twist-boat conformation. The mean plane of the five-membered thiophene ring fused to the thiazepine ring is twisted by 32.3 (3)° and 55.6 (4)° from the mean planes of the two benzene rings. In the crystal, the molecules are linked by weak C-H···N intermolecular interactions. The seven membered thiazepine ring adopts a twist boat conformation with the pairs of atoms N12/C11 and S9/C10 being oppositely oriented with respect to the C6/C7/C8 mean plane. The torsion angles around C6-C7 and C7-C8 are very close to the value of 52° reported for the corresponding torsion angle in the ideal twist boat conformation of cycloheptane. The bond lengths between C6-N12 is 1.29 (3)Å and C11-N12 is 1.39 (3)Å which is slightly less than the standard C-N value. The bond length between C8-S9 is 1.83 (9)Å and S9-C10 is 1.76 (3) Å. The sp2 and sp3 hybridization states of C10 and C8, respectively, account for the difference in the S-C bond lengths in (I). The bond lengths and angles do not show large deviations and are comparable with those reported for a similar structure (Manjula et al., 2013).

Refinement
All hydrogen atoms were located geometrically with C-H = 0.93-0.97) Å and allowed to ride on their parent atoms with U iso (H) = 1.2U eq (aromatic C).

4-(Thiophen-2-yl)-2-[4-(trifluoromethyl)phenyl]-2,3-dihydro-1,5-benzothiazepine
Crystal data C 20 H 14 F 3 NS 2 M r = 389.46 Orthorhombic, P2 1 2 1 2 1 Hall symbol: P 2ac 2ab a = 9.847 (2)  Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.