7-Bromo-3,3-dibutyl-8-methoxy-2,3-dihydro-1,5-benzothiazepin-4(5H)-one

In the title compound C18H26BrNO2S, the thiazepine ring adopts a boat conformation. The dihedral angle between the mean planes through the benzene ring and the four C atoms making up the basal plane of the boat is 35.8 (2)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) loops.

In the title compound C 18 H 26 BrNO 2 S, the thiazepine ring adopts a boat conformation. The dihedral angle between the mean planes through the benzene ring and the four C atoms making up the basal plane of the boat is 35.8 (2) . In the crystal, inversion dimers linked by pairs of N-HÁ Á ÁO hydrogen bonds generate R 2 2 (8) loops.

Comment
The title compound C 18 H 25 Br N O 2 S, was synthesized from 3,3-dibutyl-2,3-dihydro-8-methoxybenzo[b][1,4]thiazepin-4(5H)-one. The molecule is a bicyclic structure with one aromatic ring fused to a seven membered ring, on which two heteroatoms are present. The derivatives of this molecule able to provide high affinity ligands for more than one type of the receptor (Fedi et al., 2008). The compound is mainly used to treat schizophrenia and also find applications as neuroleptics, antidepressants, antihistaminic (Ganesh et al., 2011;Riedel et al., 2007). The N14-C13 bond is shorter than an usual N-C single bond [1.356 Å compared to 1.416 Å (Allen et al. 1987)]. The atoms C5, C6, C11 and C12 present in the central thiazepine ring forms a basal plane and the S10 atom as the bow, representing the boat conformation of thiazepine ring. [1,4]thiazepin-4(5H)-one in dichloromethane, acetonitrile, cooled to 5°C and added N-bromosuccinimide over a period of 15 min. Then reaction mixture was brought to room temperature, stirred for 2 h and again cooled to 5°C, then N-bromosuccinimide is added at 5°C, cooled to -5°C for 1 h, filtered, washed with cold acetonitrile and then dried in vacuum and product was recrystallized from acetonitrile solution to yield light brown blocks.

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).  View of the title molecule with 50% probability ellipsoids.

Figure 2
Packing diagram of molecule, viewed along the crystallographic b axis.

Special details
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 esds 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 > 2sigma(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.