Crystal structure of 1-(1,3-benzothiazol-2-yl)-3-(4-bromobenzoyl)thiourea

A thiourea derivative with two dissimilar functional groups was prepared and characterized. In the crystal, pairs of adjacent molecules interact via intermolecular hydrogen bonds of type C—H⋯N, C—H⋯S and N—H⋯S, resulting in molecular layers parallel to the ac plane.


Structural commentary
The X-ray structure determination revealed that the title compound crystallizes in the monoclinic space group P2 1 /n with one molecule in the asymmetric unit.The molecular geometry is illustrated in  (Samb et al., 2019;Chen et al., 2001).The bond angles around N2, N3 and C8 fall in the range 115.40 (17)-128.81(17) � and are comparable to the ideal value of 120 � observed for sp 2 hybridization.The phenyl ring and the benzothiazole ring are essentially planar with r.m.s deviations of 0.0081 and 0.0070 A ˚, respectively.The thiourea fragment (S2/N3/N2/C8/C9) is planar with a maximum deviation from its mean plane of 0.0519 (1) A ˚for N3.The 4-bromophenyl ring and the 2-benzothiazolyl groups are twisted relative to each other and form a dihedral angle of 10.45 (11) � .The two rings make dihedral angles of 8.64 ( 12) and 1.94 (11) � , respectively, with the thiourea fragment.The 4-bromobenzoyl group is trans with respect to the thiono S atom across the N3-C8 bond.The 2-benzothiazolyl ring adopts a cis conformation with respect to the thiono S atom across the N2-C8 bond.The molecule exhibits an intramolecular N-H� � �O hydrogen bond (Table 1) between the carbonyl oxygen atom and the thioamide hydrogen atom, which forms an S( 6) ring.This phenomenon is regularly noted in the case of carbonoylurea and benzoyl thiourea (Sow et al., 2009;Woei Hung & Kassim, 2010) derivatives.

Supramolecular features
In the crystal, the molecules are linked into chains that are connected by intermolecular hydrogen bonds of type C-H� � �N, C-H� � �S, and N-H� � �S (Table 1), forming molecular layers running parallel to the ac plane.Intermolecular N-H� � �S and C-H� � �N hydrogen bonds further link the molecules, forming a zigzag chain through R 2 2 (8) rings.The intermolecular C-H� � �S hydrogen bond consolidates the structure, forming rings of type R 1 2 (8) (Figs. 2 and 3).

Figure 2
Partial packing view along the a axis, H atoms are omitted for clarity.
search fragment benzothiazole thiourea yielded seventeen hits.For some hits, the bromine atom is replaced by a chlorine atom (BUDZIK; Yusof et al., 2009) or nitro group (HUWIM; Cui et al., 2009).Other results give the same chemical formula and structure but have the bromine atom in the ortho or meta position on the benzene ring [IVEWEO (Zeng et al., 2017) and SURGOE (Odame et al., 2020)].Coordination complexes based on transition metals such as rhenium (INOXUG; Schoultz et al., 2016), ruthenium (NODLUQ; Shadap et al. 2019) and rhodium (NODMAX; Shadap et al., 2019) have organic ligands that are analogues of the reported molecule.

Synthesis and crystallization
The title compound was synthesized following the procedure reported by Odame et al. (2020) with slight modification.The thiourea derivative was obtained by the reaction of potassium thiocyanate (1.9388 g, 20 mmol) with 4-bromobenzoyl chloride (4.3892 g, 20 mmol) in 25 mL of acetone and heating under reflux for 2 h to yield the 4-bromobenzoyl isothiocyanate.To the above solution was added a solution of 2-aminobenzothiazole (3 g, 20 mmol) in 25 mL of acetone.The resulting mixture was heated overnight.The solvent was removed by evaporation and the crude product was recrystallized in methanol.Yield 77%, m.p. 504 K. Analysis calculated for C 15 H 10 BrN 3 OS 2 : C, 45.92; H, 2.57; N,10.71;S,16.35. Found: C,45.90;H,2.55;N,10.69;S,16.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. H atoms were geometrically optimized (C-H = 0.95 A ˚, N-H = 0.88 A ˚) and refined as riding on their carriers with U iso (H) = 1.2U eq (C,N).

Special details
Geometry.All esds (except the esd in the dihedral angle between two l.s.planes) are estimated using the full covariance matrix.The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry.An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s.planes.

A
Figure 1A view of the title compound, showing the atom-numbering scheme.Displacement ellipsoids are plotted at the 30% probability level.

Figure 3
Figure 3 Partial packing view down the b axis showing the formation of R 2 2 (8) graph-set motifs.Hydrogen bonds are drawn as dashed lines.

Table 2
Experimental details.