N-(2,4,6-Trichloro­phen­yl)maleamic acid

K Shakuntala; Sabine Foro; B Thimme Gowda

doi:10.1107/S1600536811029436

. 2011 Jul 30;67(Pt 8):o2149. doi: 10.1107/S1600536811029436

N-(2,4,6-Trichlorophenyl)maleamic acid

K Shakuntala ^a, Sabine Foro ^b, B Thimme Gowda ^a,^*

PMCID: PMC3213587 PMID: 22091164

Abstract

In the crystal structure of the title compound, C₁₀H₆Cl₃NO₃, the conformation of the amide bond is trans. The C=O and O—H bonds of the acid group are in the relatively rare anti position to each other. This is a consequence of the intramolecular O—H⋯O hydrogen bond donated to the amide carbonyl group stabilizing the molecular structure. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into zigzag chains along the c axis.

Related literature

For studies on the effects of substituents on the structures and other aspects of N-(aryl)-amides, see: Arjunan et al. (2004 ▶); Bhat & Gowda (2000 ▶); Gowda et al. (2000 ▶, 2009 ▶); Lo & Ng (2009 ▶); Prasad et al. (2002 ▶), and on N-(aryl)-methanesulfonamides, see: Jayalakshmi & Gowda (2004 ▶). For modes of interlinking carboxylic acids by hydrogen bonds, see: Leiserowitz (1976 ▶).

Experimental

Crystal data

C₁₀H₆Cl₃NO₃
M _r = 294.51
Monoclinic,
a = 21.928 (3) Å
b = 8.2678 (8) Å
c = 13.248 (2) Å
β = 99.08 (1)°
V = 2371.7 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.77 mm⁻¹
T = 293 K
0.44 × 0.44 × 0.40 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.729, T _max = 0.749
4862 measured reflections
2436 independent reflections
2000 reflections with I > 2σ(I)
R _int = 0.012

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.094
S = 1.08
2436 reflections
161 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.55 e Å⁻³
Δρ_min = −0.44 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 datablock(s) I, global. DOI: 10.1107/S1600536811029436/bt5581sup1.cif

e-67-o2149-sup1.cif^{(15.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811029436/bt5581Isup2.hkl

e-67-o2149-Isup2.hkl^{(119.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811029436/bt5581Isup3.cml

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⋯O2ⁱ	0.84 (2)	2.04 (2)	2.884 (2)	175 (2)
O3—H3O⋯O1	0.82 (2)	1.69 (2)	2.498 (2)	168 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

KS 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

The amide moiety is an important constituent of many biologically significant compounds. As part of our studies on the effects of ring and side chain substitutions on the structures and other aspects of N-(aryl)-amides (Arjunan et al., 2004; Bhat & Gowda, 2000; Gowda et al., 2000, 2009; Prasad et al., 2002) and N-(aryl)-methanesulfonamides (Jayalakshmi & Gowda, 2004), the crystal structure of N-(2,4,6-trimethylphenyl)-maleamic acid (I) has been determined. The conformation of the amide O atom is anti to the H atom attached to the adjacent C atom, while the carboxyl O atom is syn to the H atom attached to its adjacent C atom (Fig.1). The rare anti conformation of the C=O and O–H bonds of the acid group has been observed, similar to that obsrved in N-(2,4,6-trimethylphenyl)-maleamic acid (Gowda et al., 2009) and N-phenylmaleamic acid (Lo & Ng, 2009), but contrary to the more general syn conformation observed for C=O and O–H bonds. The various modes of interlinking carboxylic acids by hydrogen bonds is described elsewhere (Leiserowitz, 1976).

The maleamic moiety includes a short intramolecular hydrogen O–H···O bond (Table 1). The C8–C9 bond length of 1.331 (3)Å clearly indicates the double bond character. The dihedral angle between the phenyl ring and the amido group –NHCO– is 83.2 (2)°. In the crystal structure, the intermolecular N–H···O hydrogen bonds link the molecules into column like chains along b-axis (Fig. 2).

Experimental

The solution of maleic anhydride (0.025 mol) in toluene (25 ml) was treated dropwise with the solution of 2,4,6-trichloroaniline (0.025 mol) also in toluene (20 ml) with constant stirring. The resulting mixture was stirred for about 30 min and set aside for an additional 30 min at room temperature for the completion of reaction. The mixture was then treated with dilute hydrochloric acid to remove the unreacted 2,4,6-trichloroaniline. The resultant solid N-(2,4,6-trichlorophenyl)maleamic acid was filtered under suction and washed thoroughly with water to remove the unreacted maleic anhydride and maleic acid. It was recrystallized to constant melting point from ethanol. The purity of the compound was checked and characterized by its infrared spectra.

Prism like colorless single crystals used in X-ray diffraction studies were grown in an ethanol solution by slow evaporation at room temperature.