4-Ethyl­amino-3-nitro­benzoic acid

Narendra Babu, S.N.; Abdul Rahim, A.S.; Abd Hamid, S.; Quah, C.K.; Fun, H.-K.

doi:10.1107/S1600536809014196

organic compounds

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ISSN: 2056-9890

Volume 65| Part 5| May 2009| Page o1079

doi:10.1107/S1600536809014196

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4-Ethylamino-3-nitrobenzoic acid

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

^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 ). 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, $[P \overline 1]$
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 ) 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[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
Δρ_max = 0.44 e Å⁻³
Δρ_min = −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); 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 ).

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.

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

	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.
	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

C₉H₁₀N₂O₄	Z = 2
M_r = 210.19	F(000) = 220
Triclinic, P1	D_x = 1.536 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 3.9354 (4) Å	Cell parameters from 3018 reflections
b = 8.4741 (9) Å	θ = 1.5–29.0°
c = 13.8106 (15) Å	µ = 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 tube	1903 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
ϕ and ω scans	θ_max = 29.0°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −5→5
T_min = 0.918, T_max = 0.996	k = −11→11
7604 measured reflections	l = −18→18

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.121	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0647P)² + 0.1132P] where P = (F_o² + 2F_c²)/3
2410 reflections	(Δ/σ)_max < 0.001
142 parameters	Δρ_max = 0.44 e Å⁻³
0 restraints	Δρ_min = −0.33 e Å⁻³

Crystal data top

C₉H₁₀N₂O₄	γ = 82.304 (4)°
M_r = 210.19	V = 454.49 (8) Å³
Triclinic, P1	Z = 2
a = 3.9354 (4) Å	Mo Kα radiation
b = 8.4741 (9) Å	µ = 0.12 mm⁻¹
c = 13.8106 (15) Å	T = 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)
T_min = 0.918, T_max = 0.996	R_int = 0.023
7604 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	0 restraints
wR(F²) = 0.121	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.44 e Å⁻³
2410 reflections	Δρ_min = −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

	x	y	z	U_iso*/U_eq
O1	−0.2816 (3)	0.09151 (12)	0.95790 (7)	0.0267 (3)
O2	0.0296 (3)	0.28327 (12)	0.93767 (7)	0.0260 (3)
O3	0.3986 (3)	0.31078 (13)	0.49289 (7)	0.0302 (3)
O4	0.3740 (3)	0.47173 (12)	0.62170 (8)	0.0272 (3)
H1O4	0.4493	0.5304	0.5797	0.041*
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)
C1	0.1130 (3)	0.24569 (15)	0.74460 (9)	0.0164 (3)
H1A	0.1501	0.3413	0.7714	0.020*
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)
C4	0.0068 (3)	−0.04224 (15)	0.66528 (9)	0.0179 (3)
H4A	−0.0235	−0.1381	0.6374	0.021*
C5	0.1453 (4)	0.07084 (16)	0.60827 (9)	0.0186 (3)
H5A	0.2077	0.0496	0.5427	0.022*
C6	0.1956 (3)	0.21795 (15)	0.64634 (9)	0.0175 (3)
C7	0.3311 (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	−0.3375	0.7516	0.021*
H8B	−0.4447	−0.2657	0.7312	0.021*
C9	−0.4293 (4)	−0.38448 (16)	0.86180 (10)	0.0206 (3)
H9A	−0.4684	−0.4841	0.8355	0.031*
H9B	−0.6428	−0.3299	0.8910	0.031*
H9C	−0.2680	−0.4038	0.9101	0.031*
H1N2	−0.299 (5)	−0.109 (2)	0.8778 (14)	0.030 (5)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0407 (6)	0.0221 (5)	0.0181 (5)	−0.0142 (4)	0.0083 (4)	−0.0012 (4)
O2	0.0395 (6)	0.0233 (5)	0.0178 (5)	−0.0145 (4)	−0.0011 (4)	−0.0033 (4)
O3	0.0478 (7)	0.0288 (6)	0.0155 (5)	−0.0165 (5)	0.0056 (4)	0.0006 (4)
O4	0.0415 (7)	0.0199 (5)	0.0215 (5)	−0.0142 (4)	0.0048 (4)	0.0009 (4)
N1	0.0222 (6)	0.0146 (5)	0.0155 (5)	−0.0032 (4)	−0.0002 (4)	0.0006 (4)
N2	0.0236 (6)	0.0144 (5)	0.0147 (5)	−0.0057 (4)	0.0004 (4)	0.0001 (4)
C1	0.0179 (6)	0.0142 (6)	0.0176 (6)	−0.0044 (5)	−0.0013 (5)	0.0004 (5)
C2	0.0181 (6)	0.0151 (6)	0.0133 (6)	−0.0025 (5)	−0.0007 (5)	0.0002 (4)
C3	0.0150 (6)	0.0142 (6)	0.0165 (6)	−0.0018 (5)	−0.0023 (5)	0.0011 (5)
C4	0.0215 (7)	0.0165 (6)	0.0162 (6)	−0.0047 (5)	−0.0016 (5)	−0.0022 (5)
C5	0.0215 (7)	0.0204 (6)	0.0143 (6)	−0.0056 (5)	0.0007 (5)	−0.0008 (5)
C6	0.0196 (7)	0.0166 (6)	0.0166 (6)	−0.0050 (5)	0.0002 (5)	0.0014 (5)
C7	0.0232 (7)	0.0192 (6)	0.0166 (6)	−0.0070 (5)	0.0007 (5)	0.0013 (5)
C8	0.0211 (7)	0.0147 (6)	0.0179 (6)	−0.0051 (5)	−0.0016 (5)	−0.0010 (5)
C9	0.0246 (7)	0.0164 (6)	0.0218 (7)	−0.0071 (5)	−0.0016 (5)	0.0007 (5)

Geometric parameters (Å, º) top

O1—N1	1.2375 (14)	C3—C4	1.4273 (18)
O2—N1	1.2273 (14)	C4—C5	1.3700 (18)
O3—C7	1.2700 (17)	C4—H4A	0.9300
O4—C7	1.2784 (16)	C5—C6	1.4043 (18)
O4—H1O4	0.8200	C5—H5A	0.9300
N1—C2	1.4506 (16)	C6—C7	1.4711 (18)
N2—C3	1.3441 (16)	C8—C9	1.5155 (18)
N2—C8	1.4634 (16)	C8—H8A	0.9700
N2—H1N2	0.832 (19)	C8—H8B	0.9700
C1—C6	1.3818 (18)	C9—H9A	0.9600
C1—C2	1.3914 (17)	C9—H9B	0.9600
C1—H1A	0.9300	C9—H9C	0.9600
C2—C3	1.4278 (17)

C7—O4—H1O4	109.5	C4—C5—H5A	119.2
O2—N1—O1	122.64 (11)	C6—C5—H5A	119.2
O2—N1—C2	118.90 (11)	C1—C6—C5	118.53 (12)
O1—N1—C2	118.46 (10)	C1—C6—C7	120.64 (12)
C3—N2—C8	123.74 (11)	C5—C6—C7	120.83 (12)
C3—N2—H1N2	117.9 (13)	O3—C7—O4	123.29 (12)
C8—N2—H1N2	118.3 (13)	O3—C7—C6	118.53 (12)
C6—C1—C2	120.49 (12)	O4—C7—C6	118.18 (12)
C6—C1—H1A	119.8	N2—C8—C9	109.98 (11)
C2—C1—H1A	119.8	N2—C8—H8A	109.7
C1—C2—C3	122.29 (11)	C9—C8—H8A	109.7
C1—C2—N1	115.93 (11)	N2—C8—H8B	109.7
C3—C2—N1	121.78 (11)	C9—C8—H8B	109.7
N2—C3—C4	120.00 (11)	H8A—C8—H8B	108.2
N2—C3—C2	124.66 (12)	C8—C9—H9A	109.5
C4—C3—C2	115.33 (11)	C8—C9—H9B	109.5
C5—C4—C3	121.59 (12)	H9A—C9—H9B	109.5
C5—C4—H4A	119.2	C8—C9—H9C	109.5
C3—C4—H4A	119.2	H9A—C9—H9C	109.5
C4—C5—C6	121.69 (12)	H9B—C9—H9C	109.5

C6—C1—C2—C3	−0.9 (2)	N2—C3—C4—C5	179.34 (13)
C6—C1—C2—N1	178.84 (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—C1	165.34 (12)	C2—C1—C6—C5	−1.6 (2)
O2—N1—C2—C3	165.04 (12)	C2—C1—C6—C7	177.98 (12)
O1—N1—C2—C3	−14.95 (19)	C4—C5—C6—C1	2.2 (2)
C8—N2—C3—C4	0.74 (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—O3	0.7 (2)
N1—C2—C3—N2	1.5 (2)	C1—C6—C7—O4	0.9 (2)
C1—C2—C3—C4	2.69 (19)	C5—C6—C7—O4	−179.51 (13)
N1—C2—C3—C4	−177.01 (11)	C3—N2—C8—C9	177.29 (12)

Hydrogen-bond geometry (Å, º) top

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.

Experimental details

Crystal data
Chemical formula	C₉H₁₀N₂O₄
M_r	210.19
Crystal system, space group	Triclinic, 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)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.12
Crystal size (mm)	0.45 × 0.05 × 0.03

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.918, 0.996
No. of measured, independent and observed [I > 2σ(I)] reflections	7604, 2410, 1903
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.682

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.121, 1.06
No. of reflections	2410
No. of parameters	142
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (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···A	D—H	H···A	D···A	D—H···A
O4—H1O4···O3ⁱ	0.8200	1.8000	2.6092 (15)	168.00
N2—H1N2···O1	0.831 (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.

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