N-(3,4-Dimethyl­phen­yl)maleamic acid

B Thimme Gowda; Miroslav Tokarčík; Jozef Kožíšek; K Shakuntala; Hartmut Fuess

doi:10.1107/S1600536809043682

. 2009 Oct 28;65(Pt 11):o2874. doi: 10.1107/S1600536809043682

N-(3,4-Dimethylphenyl)maleamic acid

B Thimme Gowda ^a,^*, Miroslav Tokarčík ^b, Jozef Kožíšek ^b, K Shakuntala ^a, Hartmut Fuess ^c

PMCID: PMC2971237 PMID: 21578460

Abstract

The title compound, C₁₂H₁₃NO₃, crystallizes with four independent molecules in the asymmetric unit. The N—H bond and the C=O bond in the amide segment are anti to each other. The C=C double bond is cis configured and an intramolecular O—H⋯O hydrogen bond is formed in each molecule. The mean planes through the aromatic ring and the amide group –NHCO– are inclined at angles of 17.4 (3), 20.8 (2), 16.2 (2) and 11.2 (3)° in the four molecules. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into ribbons along the b axis.

Related literature

For our study on the effect of ring and side-chain substitutions on the crystal structures of biologically important amides, see: Gowda, Foro, Saraswathi & Fuess (2009 ▶); Gowda, Foro, Saraswathi, Terao & Fuess (2009 ▶); Gowda, Tokarčík et al. (2009 ▶); Prasad et al. (2002 ▶). For modes of interlinking carboxylic acids by hydrogen bonds, see: Leiserowitz (1976 ▶). For a related structure, see: Lo & Ng (2009 ▶).

Experimental

Crystal data

C₁₂H₁₃NO₃
M _r = 219.23
Monoclinic,
a = 11.9003 (2) Å
b = 12.9991 (2) Å
c = 15.2641 (3) Å
β = 110.207 (2)°
V = 2215.92 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 295 K
0.48 × 0.32 × 0.31 mm

Data collection

Oxford Diffraction Xcalibur Ruby Gemini diffractometer
Absorption correction: multi-scan (CrysAlisPro; Oxford Diffraction, 2009 ▶) T _min = 0.958, T _max = 0.965
67608 measured reflections
5279 independent reflections
4100 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.134
S = 1.03
5279 reflections
577 parameters
10 restraints
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Data collection: CrysAlis Pro (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis Pro; data reduction: CrysAlis Pro; 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, 2002 ▶); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▶), PLATON (Spek, 2009 ▶) and WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809043682/bt5110sup1.cif

e-65-o2874-sup1.cif^{(34.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809043682/bt5110Isup2.hkl

e-65-o2874-Isup2.hkl^{(253.2KB, 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—H1⋯O63ⁱ	0.86	2.00	2.851 (3)	168
N2—H2N⋯O43	0.86	2.03	2.865 (3)	163
N3—H3N⋯O23ⁱ	0.86	2.07	2.916 (3)	167
N4—H4N⋯O3	0.86	2.08	2.930 (3)	169
O2—H2A⋯O1	0.88	1.62	2.481 (3)	165
O22—H22A⋯O21	0.88	1.59	2.471 (3)	176
O42—H42A⋯O41	0.88	1.61	2.487 (3)	175
O62—H62A⋯O61	0.88	1.6	2.480 (3)	176

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Symmetry code: (i) Inline graphic .

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

As a part of studying the effect of ring and side chain substitutions on the crystal structures of biologically important amides (Gowda, Foro, Saraswathi & Fuess, 2009; Gowda, Foro, Saraswathi, Terao & Fuess, 2009; Gowda, Tokarčík et al., 2009; Prasad et al., 2002), the crystal structure of N-(3,4-dimethylphenyl)-maleamic acid (I) has been determined. The asymmetric unit of the cell contains four independent molecules (Fig. 1). The conformations of the N—H and C=O bonds in the amide segment of the structure are anti to each other and those of the amide O atom and the carbonyl O atom of the acid segment are also anti to each other. But 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). In the structure of (I), 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-(2,6-dimethylphenyl)maleamic acid (Gowda, Tokarčík 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 of the acid group in N- (2,6-dimethylphenyl)succinamic acid (Gowda et al., 2009b). The various modes of interlinking carboxylic acids by hydrogen bonds is described elsewhere (Leiserowitz, 1976).

In the maleamic moiety the C8—C9, C28—C29, C48—C49 and C68—C69 bond lengths of 1.322 (5), 1.343 (4), 1.320 (4) and 1.321 (4) Å clearly indicate the double bond character. Each maleamic moiety features one intramolecular hydrogen O–H···O bond (Table 1). The mean planes through the phenyl ring and the amido group –NHCO– are inclined at the angles of 17.4 (3), 20.8 (2), 16.2 (2) and 11.2 (3)° in the first, second, third and fourth molecules, respectively. In the crystal structure, the intermolecular N–H···O hydrogen bonds link the molecules into ribbons parallel to the ab-plane of the cell (Fig. 2).

Experimental

To a solution of maleic anhydride (0.025 mol) in toluene (25 ml) was added dropwise a solution of 3,4-dimethylaniline (0.025 mol) also in toluene (20 ml) with constant stirring. The resulting mixture was warmed with stirring for over 30 min and set aside for additional 30 min at room temperature for the completion of reaction. The mixture was then treated with dilute hydrochloric acid to remove the unreacted 3,4-dimethylaniline. The resultant solid N-(3,4-dimethylphenyl)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 by elemental analysis and characterized by its infrared spectra. The single crystals used in X-ray diffraction studies were grown in an ethanol solution by slow evaporation at room temperature.