4-Ethyl­amino-3-nitro­benzoic acid

Shivanagere Nagojappa Narendra Babu; Aisyah Saad Abdul Rahim; Shafida Abd Hamid; Ching Kheng Quah; Hoong-Kun Fun

doi:10.1107/S1600536809014196

. 2009 Apr 22;65(Pt 5):o1079. doi: 10.1107/S1600536809014196

4-Ethylamino-3-nitrobenzoic acid

Shivanagere Nagojappa Narendra Babu ^a, Aisyah Saad Abdul Rahim ^a,^‡, Shafida Abd Hamid ^b, Ching Kheng Quah ^c,^§, Hoong-Kun Fun ^c,^*,^¶

PMCID: PMC2977758 PMID: 21583894

Abstract

In the title compound, C₉H₁₀N₂O₄, an intramolecular N—H⋯O hydrogen-bond interaction generates an S(6) ring motif. The nitro group is slightly twisted away from its attached benzene ring [dihedral angle = 15.29 (15)°]. In the crystal structure, molecules are stacked down the a axis caused by short O⋯O(−1−x, −y, 2−z) contacts of 2.6481 (16) Å involving the O atoms of the nitro groups. The crystal packing is consolidated by intermolecular O—H⋯O hydrogen bonds, linking the molecules into centrosymmetric dimers.

Related literature

For reference bond lengths, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For information on the use of derivatives of nitro benzoic acid as precursors for heterocyclic compounds of biological interest, see: Ishida et al. (2006 ▶). For related structures, see: Mohd. Maidin et al. (2008 ▶); Narendra Babu et al. (2009 ▶). For the synthesis of ethyl 4-ethylamino-3-nitrobenzoate, see: Li et al. (2009 ▶).

Experimental

Crystal data

C₉H₁₀N₂O₄
M _r = 210.19
Triclinic,
a = 3.9354 (4) Å
b = 8.4741 (9) Å
c = 13.8106 (15) Å
α = 89.256 (5)°
β = 84.730 (4)°
γ = 82.304 (4)°
V = 454.49 (8) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 120 K
0.45 × 0.05 × 0.03 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.918, T _max = 0.996
7604 measured reflections
2410 independent reflections
1903 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.121
S = 1.06
2410 reflections
142 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809014196/sj2618sup1.cif

e-65-o1079-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809014196/sj2618Isup2.hkl

e-65-o1079-Isup2.hkl^{(118.4KB, 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
O4—H1O4⋯O3ⁱ	0.82	1.80	2.6092 (15)	168
N2—H1N2⋯O1	0.831 (19)	2.052 (18)	2.6634 (15)	130.0 (16)

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

SNNB, ASAR and SAH gratefully acknowledge funding from the Malaysian government and Universiti Sains Malaysia (USM) under the University Research Grant (No. 1001/PFARMASI/815026). SNNB thanks USM for the Postdoctoral Research Fellowship. HKF and CKQ thank USM for the Research University Golden Goose Grant (No. 1001/PFIZIK/811012). CKQ thanks USM for a USM Fellowship.

supplementary crystallographic information

Comment

The derivatives of nitro benzoic acid are convenient precursors for the synthesis of various heterocyclic compounds of biological interest (Ishida et al., 2006). As part of our ongoing studies on new nitro benzoic acid derivatives (Mohd. Maidin et al., 2008; Narendra Babu et al., 2009), we herein present the crystal structure of the title compound.

The molecular structure is stabilized by an intramolecular N2—H1N2···O1 hydrogen bond which generates an S(6) ring motif (Bernstein et al., 1995). The bond lengths (Allen et al., 1987) and angles in the molecule (Fig. 1) are within normal ranges. The nitro groups are slightly twisted away from the attached benzene ring as indicated by the torsion angles O1—N1—C2—C1 and O2—N1—C2—C3 being 165.34 (12)° and 165.04 (12)°, respectively.

In the crystal structure, (Fig. 2), the crystal packing is consolidated by an intermolecular O4—H1O4···O3ⁱ hydrogen bond linking the molecules into dimers. There is a short O1···O1 contact (symmetry code: - 1 - x, - y, 2 - z) with distance = 2.6481 (16) which is shorter than the sum of van der Waals radii of the oxygen atoms, stacking the molecules along the a axis.

Experimental

Ethyl 4-ethylamino-3-nitro-benzoate (1.80 g, 0.0075 mol) (Li et al., 2009), and KOH (0.42 g, 0.0075 mol) was refluxed in aqueous ethanol (25 ml) for 3 h. After completion of the reaction, ethanol was distilled off and the reaction mixture was diluted with water (20 ml). The aqueous layer was washed with dichloromethane (10 x 2 ml) and then acidified with concentrated hydrochloric acid to afford a yellow precipitate as the crude product. Recrystallization of the crude product from hot ethyl acetate gave the title compound as yellow crystals suitable for X-ray analysis.