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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 5| May 2009| Page 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 Quahc§ and Hoong-Kun Func*

aSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bKulliyyah of Science, International Islamic University Malaysia (IIUM), Jalan Istana, Bandar Indera Mahkota, 25200 Kuantan, Pahang, Malaysia, and cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my

(Received 13 April 2009; accepted 16 April 2009; online 22 April 2009)

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[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For information on the use of derivatives of nitro benzoic acid as precursors for heterocyclic compounds of biological inter­est, see: Ishida et al. (2006[Ishida, T., Suzuki, T., Hirashima, S., Mizutani, K., Yoshida, A., Ando, I., Ikeda, S., Adachi, T. & Hashimoto, H. (2006). Bioorg. Med. Chem. Lett. 16, 1859-1863.]). For related structures, see: Mohd. Maidin et al. (2008[Mohd. Maidin, S. M., Abdul Rahim, A. S., Abdul Hamid, S., Kia, R. & Fun, H.-K. (2008). Acta Cryst. E64, o1501-o1502.]); Narendra Babu et al. (2009[Narendra Babu, S. N., Abdul Rahim, A. S., Osman, H., Razak, I. A. & Fun, H.-K. (2009). Acta Cryst. E65, o556.]). For the synthesis of ethyl 4-ethylamino-3-nitrobenzoate, see: Li et al. (2009[Li, H.-Y., Liu, B.-N., Tang, S.-G. & Guo, C. (2009). Acta Cryst. E65, o227.]).

[Scheme 1]

Experimental

Crystal data

  • C9H10N2O4

  • Mr = 210.19

  • Triclinic, [P \overline 1]

  • 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[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.918, Tmax = 0.996

  • 7604 measured reflections

  • 2410 independent reflections

  • 1903 reflections with I > 2σ(I)

  • Rint = 0.023
Refinement

  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.121

  • S = 1.06

  • 2410 reflections

  • 142 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.44 e Å−3

  • Δρmin = −0.33 e Å−3

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)
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information

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

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

checkCIF report


Comment top

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.

Related literature top

For reference bond lengths, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995). For information on 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 related literature, see: Cosier & Glazer (1986); Li et al. (2009).

Experimental top

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.

Refinement top

The H-atom attached to N2 was located from the difference Fourier map and refined freely. H atoms of the hydroxy groups were positioned using a rotating group model and constrained with a fixed distance of 0.82 Å. The rest of the hydrogen atoms were positioned geometrically and refined using a riding model with C—H = 0.93–0.97 Å and Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating-group model was also applied for the methyl groups.

Computing details top

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

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom numbering scheme. The dashed line indicates an intramolecular hydrogen bond.
[Figure 2] Fig. 2. The crystal packing of the title compound,viewed along the a axis. Hydrogen bonds and the short O···O contacts are shown as dashed lines.
4-Ethylamino-3-nitrobenzoic acid top
Crystal data top
C9H10N2O4Z = 2
Mr = 210.19F(000) = 220
Triclinic, P1Dx = 1.536 Mg m−3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 3.9354 (4) ÅCell parameters from 3018 reflections
b = 8.4741 (9) Åθ = 1.5–29.0°
c = 13.8106 (15) ŵ = 0.12 mm−1
α = 89.256 (5)°T = 120 K
β = 84.730 (4)°Needle, yellow
γ = 82.304 (4)°0.45 × 0.05 × 0.03 mm
V = 454.49 (8) Å3
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		2410 independent reflections
Radiation source: fine-focus sealed tube1903 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
ϕ and ω scansθmax = 29.0°, θmin = 1.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		h = −5→5
Tmin = 0.918, Tmax = 0.996k = −11→11
7604 measured reflectionsl = −18→18
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.121H atoms treated by a mixture of independent and constrained refinement
S = 1.06 w = 1/[σ2(Fo2) + (0.0647P)2 + 0.1132P]
where P = (Fo2 + 2Fc2)/3
2410 reflections(Δ/σ)max < 0.001
142 parametersΔρmax = 0.44 e Å−3
0 restraintsΔρmin = −0.33 e Å−3
Crystal data top
C9H10N2O4γ = 82.304 (4)°
Mr = 210.19V = 454.49 (8) Å3
Triclinic, P1Z = 2
a = 3.9354 (4) ÅMo Kα radiation
b = 8.4741 (9) ŵ = 0.12 mm−1
c = 13.8106 (15) ÅT = 120 K
α = 89.256 (5)°0.45 × 0.05 × 0.03 mm
β = 84.730 (4)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		2410 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		1903 reflections with I > 2σ(I)
Tmin = 0.918, Tmax = 0.996Rint = 0.023
7604 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.121H atoms treated by a mixture of independent and constrained refinement
S = 1.06Δρmax = 0.44 e Å−3
2410 reflectionsΔρmin = −0.33 e Å−3
142 parameters
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat [Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107] operating at 120.0 (1) K.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O1−0.2816 (3)0.09151 (12)0.95790 (7)0.0267 (3)
O20.0296 (3)0.28327 (12)0.93767 (7)0.0260 (3)
O30.3986 (3)0.31078 (13)0.49289 (7)0.0302 (3)
O40.3740 (3)0.47173 (12)0.62170 (8)0.0272 (3)
H1O40.44930.53040.57970.041*
N1−0.0961 (3)0.17166 (13)0.90601 (8)0.0175 (2)
N2−0.2305 (3)−0.12944 (13)0.82002 (8)0.0174 (2)
C10.1130 (3)0.24569 (15)0.74460 (9)0.0164 (3)
H1A0.15010.34130.77140.020*
C2−0.0252 (3)0.13158 (15)0.80371 (9)0.0155 (3)
C3−0.0921 (3)−0.01649 (14)0.76646 (9)0.0152 (3)
C40.0068 (3)−0.04224 (15)0.66528 (9)0.0179 (3)
H4A−0.0235−0.13810.63740.021*
C50.1453 (4)0.07084 (16)0.60827 (9)0.0186 (3)
H5A0.20770.04960.54270.022*
C60.1956 (3)0.21795 (15)0.64634 (9)0.0175 (3)
C70.3311 (4)0.34040 (16)0.58304 (10)0.0194 (3)
C8−0.2853 (4)−0.28286 (15)0.78103 (10)0.0177 (3)
H8A−0.0688−0.33750.75160.021*
H8B−0.4447−0.26570.73120.021*
C9−0.4293 (4)−0.38448 (16)0.86180 (10)0.0206 (3)
H9A−0.4684−0.48410.83550.031*
H9B−0.6428−0.32990.89100.031*
H9C−0.2680−0.40380.91010.031*
H1N2−0.299 (5)−0.109 (2)0.8778 (14)0.030 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0407 (6)0.0221 (5)0.0181 (5)−0.0142 (4)0.0083 (4)−0.0012 (4)
O20.0395 (6)0.0233 (5)0.0178 (5)−0.0145 (4)−0.0011 (4)−0.0033 (4)
O30.0478 (7)0.0288 (6)0.0155 (5)−0.0165 (5)0.0056 (4)0.0006 (4)
O40.0415 (7)0.0199 (5)0.0215 (5)−0.0142 (4)0.0048 (4)0.0009 (4)
N10.0222 (6)0.0146 (5)0.0155 (5)−0.0032 (4)−0.0002 (4)0.0006 (4)
N20.0236 (6)0.0144 (5)0.0147 (5)−0.0057 (4)0.0004 (4)0.0001 (4)
C10.0179 (6)0.0142 (6)0.0176 (6)−0.0044 (5)−0.0013 (5)0.0004 (5)
C20.0181 (6)0.0151 (6)0.0133 (6)−0.0025 (5)−0.0007 (5)0.0002 (4)
C30.0150 (6)0.0142 (6)0.0165 (6)−0.0018 (5)−0.0023 (5)0.0011 (5)
C40.0215 (7)0.0165 (6)0.0162 (6)−0.0047 (5)−0.0016 (5)−0.0022 (5)
C50.0215 (7)0.0204 (6)0.0143 (6)−0.0056 (5)0.0007 (5)−0.0008 (5)
C60.0196 (7)0.0166 (6)0.0166 (6)−0.0050 (5)0.0002 (5)0.0014 (5)
C70.0232 (7)0.0192 (6)0.0166 (6)−0.0070 (5)0.0007 (5)0.0013 (5)
C80.0211 (7)0.0147 (6)0.0179 (6)−0.0051 (5)−0.0016 (5)−0.0010 (5)
C90.0246 (7)0.0164 (6)0.0218 (7)−0.0071 (5)−0.0016 (5)0.0007 (5)
Geometric parameters (Å, º) top
O1—N11.2375 (14)C3—C41.4273 (18)
O2—N11.2273 (14)C4—C51.3700 (18)
O3—C71.2700 (17)C4—H4A0.9300
O4—C71.2784 (16)C5—C61.4043 (18)
O4—H1O40.8200C5—H5A0.9300
N1—C21.4506 (16)C6—C71.4711 (18)
N2—C31.3441 (16)C8—C91.5155 (18)
N2—C81.4634 (16)C8—H8A0.9700
N2—H1N20.832 (19)C8—H8B0.9700
C1—C61.3818 (18)C9—H9A0.9600
C1—C21.3914 (17)C9—H9B0.9600
C1—H1A0.9300C9—H9C0.9600
C2—C31.4278 (17)
C7—O4—H1O4109.5C4—C5—H5A119.2
O2—N1—O1122.64 (11)C6—C5—H5A119.2
O2—N1—C2118.90 (11)C1—C6—C5118.53 (12)
O1—N1—C2118.46 (10)C1—C6—C7120.64 (12)
C3—N2—C8123.74 (11)C5—C6—C7120.83 (12)
C3—N2—H1N2117.9 (13)O3—C7—O4123.29 (12)
C8—N2—H1N2118.3 (13)O3—C7—C6118.53 (12)
C6—C1—C2120.49 (12)O4—C7—C6118.18 (12)
C6—C1—H1A119.8N2—C8—C9109.98 (11)
C2—C1—H1A119.8N2—C8—H8A109.7
C1—C2—C3122.29 (11)C9—C8—H8A109.7
C1—C2—N1115.93 (11)N2—C8—H8B109.7
C3—C2—N1121.78 (11)C9—C8—H8B109.7
N2—C3—C4120.00 (11)H8A—C8—H8B108.2
N2—C3—C2124.66 (12)C8—C9—H9A109.5
C4—C3—C2115.33 (11)C8—C9—H9B109.5
C5—C4—C3121.59 (12)H9A—C9—H9B109.5
C5—C4—H4A119.2C8—C9—H9C109.5
C3—C4—H4A119.2H9A—C9—H9C109.5
C4—C5—C6121.69 (12)H9B—C9—H9C109.5
C6—C1—C2—C3−0.9 (2)N2—C3—C4—C5179.34 (13)
C6—C1—C2—N1178.84 (11)C2—C3—C4—C5−2.10 (19)
O2—N1—C2—C1−14.67 (18)C3—C4—C5—C6−0.3 (2)
O1—N1—C2—C1165.34 (12)C2—C1—C6—C5−1.6 (2)
O2—N1—C2—C3165.04 (12)C2—C1—C6—C7177.98 (12)
O1—N1—C2—C3−14.95 (19)C4—C5—C6—C12.2 (2)
C8—N2—C3—C40.74 (19)C4—C5—C6—C7−177.39 (13)
C8—N2—C3—C2−177.68 (12)C1—C6—C7—O3−178.93 (12)
C1—C2—C3—N2−178.83 (12)C5—C6—C7—O30.7 (2)
N1—C2—C3—N21.5 (2)C1—C6—C7—O40.9 (2)
C1—C2—C3—C42.69 (19)C5—C6—C7—O4−179.51 (13)
N1—C2—C3—C4−177.01 (11)C3—N2—C8—C9177.29 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O4···O3i0.821.802.6092 (15)168
N2—H1N2···O10.831 (19)2.052 (18)2.6634 (15)130.0 (16)
Symmetry code: (i) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formulaC9H10N2O4
Mr210.19
Crystal system, space groupTriclinic, P1
Temperature (K)120
a, b, c (Å)3.9354 (4), 8.4741 (9), 13.8106 (15)
α, β, γ (°)89.256 (5), 84.730 (4), 82.304 (4)
V (Å3)454.49 (8)
Z2
Radiation typeMo Kα
µ (mm−1)0.12
Crystal size (mm)0.45 × 0.05 × 0.03
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.918, 0.996
No. of measured, independent and
observed [I > 2σ(I)] reflections		7604, 2410, 1903
Rint0.023
(sin θ/λ)max (Å−1)0.682
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.121, 1.06
No. of reflections2410
No. of parameters142
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.44, −0.33

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O4···O3i0.82001.80002.6092 (15)168.00
N2—H1N2···O10.831 (19)2.052 (18)2.6634 (15)130.0 (16)
Symmetry code: (i) −x+1, −y+1, −z+1.
 

Footnotes

‡Additional correspondence author, e-mail: aisyah@usm.my.

§Thomson Reuters ResearcherID: A-5525-2009.

Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

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.

References

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 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 5| May 2009| Page o1079
doi:10.1107/S1600536809014196
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