N,N′-Bis(2-chloro­phen­yl)succinamide

B S Saraswathi; Sabine Foro; B Thimme Gowda

doi:10.1107/S1600536811013407

. 2011 Apr 16;67(Pt 5):o1139. doi: 10.1107/S1600536811013407

N,N′-Bis(2-chlorophenyl)succinamide

B S Saraswathi ^a, Sabine Foro ^b, B Thimme Gowda ^a,^*

PMCID: PMC3089196 PMID: 21754448

Abstract

There is one half-molecule in the asymmetric unit of the title compound, C₁₆H₁₄Cl₂N₂O₂, with a center of symmetry at the mid-point of the central C—C bond. The N—H and C=O bonds in the C—NH—C(O)—C fragment are anti to each other and the amide O atom is anti to the H atoms attached to the adjacent C atoms. However, the conformation of the N—H bond in the amide fragments is syn to the ortho-chloro groups in the adjacent benzene rings. The dihedral angle between the benzene ring and the NH—C(O)—CH₂ fragment is 47.0 (2)°. In the crystal, a series of N—H⋯O intermolecular hydrogen bonds link the molecules into chains along the b axis.

Related literature

For our study of the effect of substituents on the structures of N-(aryl)-amides, see: Gowda et al. (2000 ▶); Saraswathi et al. (2011a ▶,b ▶) and on N-(aryl)-methanesulfonamides, see: Gowda et al. (2007 ▶). For a similar structure, see Pierrot et al. (1984 ▶).

Experimental

Crystal data

C₁₆H₁₄Cl₂N₂O₂
M _r = 337.19
Monoclinic,
a = 4.820 (2) Å
b = 11.445 (3) Å
c = 14.242 (4) Å
β = 98.10 (3)°
V = 777.8 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.43 mm⁻¹
T = 293 K
0.44 × 0.08 × 0.04 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.835, T _max = 0.983
2501 measured reflections
1563 independent reflections
900 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.075
wR(F ²) = 0.139
S = 1.16
1563 reflections
103 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811013407/fl2341sup1.cif

e-67-o1139-sup1.cif^{(14.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811013407/fl2341Isup2.hkl

e-67-o1139-Isup2.hkl^{(77.1KB, 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
N1—H1N⋯O1ⁱ	0.86 (2)	2.11 (2)	2.936 (4)	161 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

BSS thanks the University Grants Commission, Government of India, New Delhi, for the award of a research fellowship under its faculty improvement program.

supplementary crystallographic information

Comment

Amide and sulfonamide moieties are important constituents of many biologically significant compounds. As a part of studying the substituent effects on structures of this class of compounds(Gowda et al., 2000, 2007; Saraswathi et al., 2011a,b), the structure of (I) has been determined (Fig.1). (I) sits on a center of symmetry passing through the mid-point of the central C—C bond to give a half molecule per asymmetric unit. This is similar to that obseved in bis(2-chlorophenylaminocarbonylmethyl)disulfide (II)(Pierrot et al., 1984), N,N-bis(2-methylphenyl)-succinamide (III)(Saraswathi et al., 2011a) and N,N-bis(3-chlorophenyl)- succinamide (III)(Saraswathi et al., 2011b).

The conformations of the N—H and C=O bonds in the C—NH—C(O)—C segments are anti to each other and the amide O atoms are anti to the H atoms attached to the adjacent C atoms. But the conformations of the N—H bonds in the amide fragments are syn to the ortho- chloro groups in the adjacent benzene rings, in contrast to the anti conformations observed with respect to the ortho-methyl groups in (III) and with respect to the meta-chloro groups in (IV).

The dihedral angle between the benzene ring and the NH—C(O)—CH₂ segment in the two halves of the molecule is 47.0 (2)°, compared to the values of 62.1 (2)° in (III) and 32.8 (1)° in (Iv).

The torsion angles of N1–C7–C8–C8a and O1–C7–C8–C8a in (I) are 172.2 (5)° and -7.8 (4)°, in contrast to the values of 150.9 (3)° and -30.5 (4)° in (III) and -175.4 (2)° and 5.9 (4)° in (IV). The differences in the torsion angles may be due to the steric hindrances caused by the different substituents.

Similarly, the torsion angles of C2—C1—N1—C7 and C6—C1—N1—C7 are -47.6 (6)° and 133.7 (4)°, compared to the values of -64.0 (4)° and 117.6 (3)° in (III) and -35.0 (3)° and 147.5 (2)° in (IV).

The packing of molecules in the crystal linked by of N—H···O hydrogen bonds (Table 1) is shown in Fig. 2.

Experimental

Succinic anhydride (0.01 mol) in toluene (25 ml) was treated drop wise with 2-chloroaniline (0.01 mol) also in toluene (20 ml) with constant stirring. The resulting mixture was stirred for one hour and set aside for an additional hour at room temperature for completion of the reaction. The mixture was then treated with dilute hydrochloric acid to remove unreacted 2-chloroaniline. The resultant solid N-(2-chlorophenyl)-succinamic acid was filtered under suction and washed thoroughly with water to remove the unreacted succinic anhydride and succinic acid. The compound was recrystallized to constant melting point from ethanol. The purity of the compound was checked by elemental analysis and characterized by its infrared and NMR spectra.

The N-(2-chlorophenyl)succinamic acid obtained was then treated with phosphorous oxychloride and excess of 2-chloroaniline at room temperature with constant stirring. The resultant mixture was stirred for 4 h, kept aside for additional 6 h for completion of the reaction and poured slowly into crushed ice with constant stirring. It was kept aside for a day. The resultant solid, N,N-bis(2-chlorophenyl)- succinamide was filtered under suction, washed thoroughly with water, dilute sodium hydroxide solution and finally with water. It was recrystallized to constant melting point from a mixture of acetone and chloroform. The purity of the compound was checked by elemental analysis, and characterized by its infrared and NMR spectra.

Needle like colorless single crystals used in the X-ray diffraction studies were were grown in a mixture of acetone and chloroform at room temperature.