Crystal structure of 4-methoxy-N-(piperidine-1-carbonothioyl)benzamide

In the title benzoylthiourea derivative (MPiCB), the piperidine ring has a chair conformation and its mean plane is inclined to the 4-methoxybenzene ring by 63.0 (3)°.

In the title compound, C 14 H 18 N 2 O 2 S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-methoxybenzoyl ring, with a dihedral angle of 63.0 (3) . The central N-C( S)-N(H)-C( O) bridge is twisted with an N-C-N-C torsion angle of 74.8 (6) . In the crystal, molecules are linked by N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming chains along the c-axis direction. Adjacent chains are linked by C-HÁ Á Á interactions, forming layers parallel to the ac plane. The layers are linked by offsetinteractions [intercentroid distance = 3.927 (3) Å ], forming a supramolecular three-dimensional structure.

Structural commentary
The molecular structure of the title compound, MPiCB, is illustrated in Fig. 1. The geometrical parameters are similar to those observed for 4-methoxy-N-[(pyrrolidin-1-yl)carbothioyl]benzamide (MPCB; Suhud et al. 2015a). The 4-methoxybenzoyl and piperidine fragments adopt a trans-cis conformation with respect to the thiono S atom across the C8-N1 bond, with the piperidine ring having a chair conformation. The mean plane of the piperidine ring is twisted with respect to the 4-methoxy benzoyl ring with a dihedral angle of 63.0 (3) . The central N-C( S)-N(H)-C( O) bridge is twisted with an N2-C8-N1-C7 torsion angle of 74.8 (6) . The methoxy group lies in the plane of the benzene ring, with the C14-O2-C4-C3 torsion angle being 180.0 (4) .

Supramolecular features
In the crystal of MPiCB, neighbouring molecules are linked by N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming chains along the c-axis direction (Table 1 and Fig. 2). Adjacent chains are linked by C-HÁ Á Á interactions, involving a piperidine H atom and the electrons of the benzene ring, forming layers parallel to the ac plane (Table 1 and Fig. 3). The layers are linked by offsetstacking interactions involving the benzene rings, forming a supramolecular three-dimensional structure as illustrated in Fig. 3 [CgÁ Á ÁCg i = 3.927 (3) Å ; Cg is the centroid of the C1-C6 ring; interplanar distance = 3.517 (2) Å ; slippage = 1.747 Å ; symmetry code: (i) Àx, Ày + 2, Àz + 2]. A view of the molecular structure of the title compound (MPiCB), with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level. Table 1 Hydrogen-bond geometry (Å , ).

Figure 2
A view along the a axis of the crystal packing of the title compound (MPiCB). Hydrogen bonds (see Table 1) are shown as dashed lines.
asymmetric unit with slightly different conformations. For example, the mean plane of the piperidine rings are inclined to the benzene rings by 58.97 (11) and 64.11 (11) , compared to 63.13 (3)

Synthesis and crystallization
Benzoyl chloride (0.01 mol) was added slowly to ammonium thiocyanate (0.01 mol) in acetone and the mixture was stirred for 30 min at room temperature. A white precipitate of ammonium chloride was filtered off and the filtrate was cooled in an ice bath (278-283 K) for about 15 min. A cold solution (278-283 K) of piperidine (0.01 mol) in acetone was added to the benzoyl isothiocyanate and the mixture was left for 3 h at room temperature. A yellowish precipitate was formed, filtered and washed with cold water to give pale-yellow crystals (yield 87%, m.p. 401-402 K).
The infrared spectrum of MPiCB shows the characteristic signals for (NH) 3300, (O-CH 3 ) 2900, (C O) 1609, (C-C benzene ) 1460, (C-O stretching ) 1327 and v(C S) 1252 cm À1 . The 1 H NMR spectrum exhibits the H(N) group at 8.35 Hz, while the 13 C NMR signal of the C S and C O groups appear at 174.66 and 163.19 Hz, respectively.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The NH H atom was located in a difference-Fourier map and freely refined. The C-bound H atoms were included in calculated positions and refined in a riding-model approximation: C-H = 0.93-0.97 Å with U iso (H) = 1.2U eq (C).    program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).

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. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness 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 threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) 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.