4-Chloro-N-(2,6-dichloro­phen­yl)benzamide

Miroslav Tokarčík; B Thimme Gowda; Jozef Kožíšek; B P Sowmya; Hartmut Fuess

doi:10.1107/S160053680902265X

. 2009 Jun 20;65(Pt 7):o1637–o1638. doi: 10.1107/S160053680902265X

4-Chloro-N-(2,6-dichlorophenyl)benzamide

Miroslav Tokarčík ^a, B Thimme Gowda ^b, Jozef Kožíšek ^a, B P Sowmya ^b, Hartmut Fuess ^c,^*

PMCID: PMC2969447 PMID: 21582902

Abstract

The title compound, C₁₃H₈Cl₃NO, crystallizes with four molecules in the asymmetric unit. In the molecular structure, the conformations of the central amide –CONH group show a wide range of dihedral angles with respect to the attached aromatic rings (benzoyl and anilino). The dihedral angles between the amide group and the benzoyl ring are 8.1 (3), 4.3 (3), 27.8 (1) and 32.7 (2)° in the four molecules. The amide group is twisted out of the plane of the anilino ring, as shown by the dihedral angles of 85.4 (1), 74.3 (1), 88.1 (1) and 77.6 (1)° in the four molecules. The aromatic rings are oriented at dihedral angles of 86.6 (1), 78.0 (1), 60.3 (1) and 69.8 (1)° in the four molecules. The crystal structure is stabilized via intermolecular N—H⋯O hydrogen bonds, aromatic aromatic interactions, short Cl⋯Cl contacts and C—H⋯Cl hydrogen bonds. Intermolecular hydrogen bonds connect the molecules into two distinct chains running along the c axis of the crystal. One molecule forms an inversion dimer in which the main interactions are π–π stacking [centroid–centroid distances = 3.749 (1) and 3.760 (1) Å] and a short Cl⋯Cl contact of 3.408 (1) Å.

Related literature

For the biological activity of benzamide and benzanilide derivatives, see: Glaser (2007 ▶); Pasha et al. (2008 ▶); Brunhofer et al. (2008 ▶); Calderone et al. (2006 ▶); Stauffer et al. (2000 ▶); Lindgren et al. (2001 ▶). For anion recognition, see: Kang et al. (2006 ▶); Sun et al. (2009 ▶). For theoretical study of internal rotations, see: Nishikawa et al. (2005 ▶). For related structures, see: Bowes et al. (2003 ▶); Gowda et al. (2003 ▶); Saeed et al. (2008 ▶).

Experimental

Crystal data

C₁₃H₈Cl₃NO
M _r = 300.55
Monoclinic,
a = 16.9411 (3) Å
b = 16.3246 (2) Å
c = 19.5505 (3) Å
β = 95.3678 (13)°
V = 5383.11 (14) Å³
Z = 16
Mo Kα radiation
μ = 0.67 mm⁻¹
T = 295 K
0.51 × 0.11 × 0.09 mm

Data collection

Oxford Diffraction Xcalibur diffractometer
Absorption correction: analytical [CrysAlis RED (Oxford Diffraction, 2008 ▶), based on Clark & Reid (1995 ▶)] T _min = 0.754, T _max = 0.944
180094 measured reflections
10264 independent reflections
5984 reflections with I > 2σ(I)
R _int = 0.053

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.107
S = 0.98
10278 reflections
670 parameters
15 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2001 ▶); software used to prepare material for publication: SHELXL97, PLATON (Spek, 2009 ▶) and WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680902265X/zl2218sup1.cif

e-65-o1637-sup1.cif^{(35.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680902265X/zl2218Isup2.hkl

e-65-o1637-Isup2.hkl^{(492.5KB, hkl)}

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
N1A—H1N⋯O1Dⁱ	0.855 (16)	2.066 (17)	2.882 (2)	159 (2)
N1B—H2N⋯O1Cⁱⁱ	0.816 (15)	2.117 (17)	2.880 (2)	156 (2)
N1C—H3N⋯O1B	0.842 (15)	2.054 (16)	2.875 (2)	165 (2)
N1D—H4N⋯O1Aⁱⁱⁱ	0.844 (16)	1.942 (19)	2.728 (2)	154 (2)
C7A—H7A⋯O1Dⁱ	0.93	2.59	3.489 (3)	164
C10C—H10C⋯Cl2B^iv	0.93	2.82	3.599 (3)	142

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

MT and JK thank the Grant Agency of the Slovak Republic (VEGA 1/0817/08) and Structural Funds, Interreg IIIA, for financial support in purchasing the diffractometer.

supplementary crystallographic information

Comment

Various biological activities of benzamide and benzanilide derivatives have been reported in the literature: benzamide based histone deacetylase inhibitors (Glaser 2007), N-phenylbenzamides as antimicrobial agents (Pasha et al., 2008), benzanilides with spasmolytic activity (Brunhofer et al., 2008), benzanilide derivatives as effective potassium channel openers (Calderone et al., 2006), N-phenyl benzamides as estrogen receptor ligands (Stauffer et al., 2000), N-substituted benzamides with immuno-modulatory activity (Lindgren et al., 2001). In supramolecular chemistry, aromatic amides are widely used for anion recognition (Kang et al., 2006). Sun et al. (2009) reported nitrophenylbenzamide based chemosensors toward cyanide in aqueous environment. Nishikawa et al. (2005) performed DFT-calculations of barriers to internal rotations in aromatic polyamides, including benzanilide.

The title compound, C₁₃H₈Cl₃NO, (Fig.1), has four unique molecules in the asymmetric unit (further marked as A, B, C and D). In the molecular structure, the conformations of the central amide group CONH with respect to the attached aromatic rings (benzoyl C2/C7, anilino C8/C13) show a wide range of dihedral angle values, which is an indication that the energy of intermolecular interactions is comparable to the barriers of internal rotations. The dihedral angle between the amide group and the benzoyl ring is 8.1 (3), 4.3 (3), 27.8 (1) and 32.7 (2)° in the molecules A, B, C and D, respectively. The amide group is heavily twisted out of the plane of the anilino ring, with dihedral angles of 85.4 (1), 74.3 (1), 88.1 (1), 77.6 (1)° for the molecules A, B, C and D, respectively. This conformation can be attributed to the steric effect of the bulky chloro groups in ortho positions. We recall that the corresponding dihedral angle in the parent molecule benzanilide is ca 31° (Bowes, et al., 2003). The aromatic rings (benzoyl and anilino) are oriented at dihedral angles of 86.6 (1), 78.0 (1), 60.3 (1) and 69.8 (1)° in the molecules A, B, C and D, respectively. In benzanilide, the aromatic rings make a dihedral angle of ca 61°. The bond lengths and bond angles lie within the ranges expected for similar compounds. The endocyclic bond angles in both aromatic rings are sligtly distorted from the ideal value of 120°, reflecting the chloro-substitution effect on the benzene rings. The orientation of an amide group with respect to aromatic rings strongly depends on the local crystal field, which is manifested by significant differences in the torsion angles describing the conformations in the molecules A, B, C and D.

The crystal structure is stabilized by intermolecular N—H···O hydrogen bonds, aromatic aromatic interactions, short Cl···Cl contacts and weak C—H···Cl hydrogen bonds. Intermolecular N—H···O hydrogen bonds connect the molecules into two distinct chains running along the c axis of the crystal (Fig. 2). The first chain is linked by hydrogen bonds arising between amidic N, O atoms of the molecules A and D. The second chain is linked by hydrogen bonds arising between amidic N, O atoms of the molecules B and C. The chains are coupled via stacking interactions. The two most important π - π stacking formations, which we found using the PLATON software (Spek, 2009), are: The stacking between the benzoyl rings of the molecule C at the positions (x,y,z) and (1 - x,1 - y,1 - z). The interplanar distance is 3.538 Å, offset 1.241 Å and ring-centroids separation 3.749 Å. The second stacking is between the anilino rings of the molecule C at the positions (x, y, z) and (1 - x, -y, 1 - z). The interplanar distance is 3.411 Å, offset 1.582 Å and ring-centroids separation 3.760 Å. The molecule C forms an interesting inversion dimer (Fig. 3), with a head-to-tail arrangement. The dimer is stabilized by π - π interaction, a short Cl···Cl contact of 3.408 (1) Å, and possibly dipolar interaction between carbonyl group dipoles. A non-conventional C—H···Cl hydrogen bond (C10c—H10c···Cl2b) adds to the mosaic of interactions in the crystal structure of the title compound. The H10c···Cl2b distance of 2.82 Å is 0.13 Å shorter than the the sum of van der Waals radii for H and Cl.

Experimental

The title compound was prepared according to the method of Gowda et al. (2003). Single crystals used in X-ray diffraction studies were obtained by slow evaporation of its ethanolic solution at room temperature. The purity of the compound was checked by determining its melting point (172–173 °C). The compound was characterized via IR and NMR spectroscopy. IR (KBr, cm^-1): 3271.0 m (N–H stretch), 1654.8 s (C=O stretch), 1299.9 m (C–N stretch). [s = strong band, m = medium band]. ¹H NMR (CDCl₃, 300 MHz, p.p.m.): 7.67 (H–N), 7.40 d (H-3,7), 7.23 d (H-11), 7.88 d (H-3,7), 7.46 d (H-4,6). ¹³C NMR (CDCl₃, 75.5 MHz, p.p.m.): 164.8 (C=O), 132.0 (C-2), 128.9 (C-3,7), 129.1 (C-4,6), 133.7 (C-5), 138.7 (C-8), 131.6 (C-9,13), 128.8 (C-10,12), 128.6 (C-11).