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Acta Crystallogr Sect E Struct Rep Online. 2010 June 1; 66(Pt 6): o1484.
Published online 2010 May 29. doi:  10.1107/S160053681001946X
PMCID: PMC2979349

2-Methyl­amino-5-nitro­benzoic acid

Abstract

The title compound, C8H8N2O4, is almost planar (r.m.s. deviation = 0.037 Å) and an intra­molecular N—H(...)O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of O—H(...)O hydrogen bonds generate R 2 2(8) loops. Inter­molecular N—H(...)O hydrogen bonds (involving the same H atom that forms the intra­molecular hydrogen bond) link the dimers into infinite sheets lying parallel to (102).

Related literature

For background to the medicinal properties of benzodiazepines, see: Blank et al. (2009 [triangle]); Kamal et al. (2010 [triangle]). For a related structure, see: Dhaneshwar & Pant (1972 [triangle]). For graph-set theory, see: Bernstein et al. (1995 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o1484-scheme1.jpg

Experimental

Crystal data

  • C8H8N2O4
  • M r = 196.16
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o1484-efi1.jpg
  • a = 7.2541 (12) Å
  • b = 14.037 (2) Å
  • c = 8.5972 (14) Å
  • β = 103.673 (6)°
  • V = 850.6 (2) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.13 mm−1
  • T = 296 K
  • 0.34 × 0.12 × 0.10 mm

Data collection

  • Bruker Kappa APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.979, T max = 0.988
  • 6739 measured reflections
  • 1667 independent reflections
  • 931 reflections with I > 2σ(I)
  • R int = 0.051

Refinement

  • R[F 2 > 2σ(F 2)] = 0.051
  • wR(F 2) = 0.156
  • S = 0.95
  • 1667 reflections
  • 129 parameters
  • H-atom parameters constrained
  • Δρmax = 0.25 e Å−3
  • Δρmin = −0.27 e Å−3

Data collection: APEX2 (Bruker, 2007 [triangle]); cell refinement: SAINT (Bruker, 2007 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 [triangle]) and PLATON (Spek, 2009 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]) and PLATON.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681001946X/hb5463sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053681001946X/hb5463Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors acknowledge the provision of funds for the purchase of diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha. ARR also acknowledges the Higher Education Commission, Government of Pakistan, for generous support of a research project (20-819).

supplementary crystallographic information

Comment

The benzodiazepines constitute a very diverse class of heterocyclic compounds with plethora of biological activities such as anti-caner (Kamal et al., 2010) and anti-HIV (Blank et al., 2009) agent. The title compound (I, Fig. 1) was synthesized as a precursor for the synthesis of benzodiazepine derivative and it will also be utilized for the metal complexation.

The crystal structures of N-methylanthranilic acid (II) (Dhaneshwar & Pant, 1972) has been published. The title compound differs from (II) due to substitution of nitro group at at position five.

The asymmetric unit of title compound is essentially planar with r. m. s. deviation of 0.0366 Å from the least square plane of (C1—C8/N1/N2/O1/O2/O3). There exist a S(6) ring motif (Bernstein et al., 1995) due to N—H···O type of intramolecular H-bondings. The molecules are dimerised due to inversion related O—H···O type of H-bondings with R22(8) ring motifs. The dimers are interlinked in the form of infinite two dimensional polymeric sheets due to H-bonding of N—H···O type (Fig. 2).

Experimental

To HNO3 (1.83 g, 0.03 mol) taken in an ice chilled round bottom flask the H2SO4 (2.6 g, 0.026 mol) was added as drops with constant stirring. A solution of N-methylanthranilic acid (2 g, 0.01 mol) in EtOAc (25 ml) was added as drops to the nitrating mixture in ice chilled water bath and stirred for half an hour followed by 3 hours reflux. The reaction mixture was neutralized and extracted with EtOAc (3 × 30 ml). The organic layer was dried over anhydrous Na2SO4 and concentrated under reduce pressure that afforded purple needles of (I) upon standing.

Refinement

Although H atoms were appeared in difference Fourier map but were positioned geometrically with (C-H = 0.93–0.96 and O-H = 0.82 Å) and refined as riding with Uiso(H) = xUeq(C), where x = 1.5 for methyl and hydroxy H-atoms and x = 1.2 for other H atoms.

Figures

Fig. 1.
View of (I) with displacement ellipsoids drawn at the 50% probability level. The dotted line indicate the intramolecular H-bond.
Fig. 2.
The partial packing diagram of (I), which shows that molecules form polymeric chains extending along the b-axis.

Crystal data

C8H8N2O4F(000) = 408
Mr = 196.16Dx = 1.532 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 931 reflections
a = 7.2541 (12) Åθ = 2.8–26.0°
b = 14.037 (2) ŵ = 0.13 mm1
c = 8.5972 (14) ÅT = 296 K
β = 103.673 (6)°Needle, colorless
V = 850.6 (2) Å30.34 × 0.12 × 0.10 mm
Z = 4

Data collection

Bruker Kappa APEXII CCD diffractometer1667 independent reflections
Radiation source: fine-focus sealed tube931 reflections with I > 2σ(I)
graphiteRint = 0.051
Detector resolution: 7.50 pixels mm-1θmax = 26.0°, θmin = 2.8°
ω scansh = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2005)k = −17→12
Tmin = 0.979, Tmax = 0.988l = −10→10
6739 measured reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.051Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.156H-atom parameters constrained
S = 0.95w = 1/[σ2(Fo2) + (0.0901P)2] where P = (Fo2 + 2Fc2)/3
1667 reflections(Δ/σ)max < 0.001
129 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = −0.27 e Å3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles
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)

xyzUiso*/Ueq
O10.5419 (3)0.38658 (12)0.5049 (2)0.0518 (7)
O20.7127 (3)0.49628 (11)0.4158 (3)0.0573 (8)
O31.2269 (3)0.42409 (14)0.1896 (3)0.0729 (9)
O41.3096 (3)0.27893 (14)0.1606 (3)0.0672 (8)
N10.6259 (3)0.20268 (13)0.4642 (3)0.0468 (8)
N21.2080 (3)0.33798 (16)0.2050 (3)0.0520 (9)
C10.7967 (3)0.33700 (15)0.3914 (3)0.0356 (8)
C20.7635 (3)0.23711 (16)0.4028 (3)0.0380 (8)
C30.8868 (3)0.17368 (17)0.3470 (3)0.0421 (9)
C41.0304 (4)0.20647 (17)0.2851 (3)0.0445 (9)
C51.0588 (3)0.30381 (17)0.2745 (3)0.0412 (9)
C60.9435 (4)0.36766 (16)0.3270 (3)0.0405 (8)
C70.6728 (4)0.40694 (16)0.4424 (3)0.0404 (9)
C80.5800 (4)0.10286 (17)0.4683 (4)0.0530 (11)
H10.559630.242470.504270.0562*
H20.636120.531600.443250.0859*
H30.868640.108330.353120.0505*
H41.109700.163750.249880.0534*
H60.964730.432630.319040.0486*
H8A0.688220.068780.528570.0796*
H8B0.545750.078390.361010.0796*
H8C0.475520.094990.517890.0796*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0570 (13)0.0296 (10)0.0792 (14)0.0016 (8)0.0367 (11)0.0003 (9)
O20.0657 (13)0.0256 (11)0.0921 (16)0.0005 (9)0.0418 (12)−0.0015 (9)
O30.0793 (16)0.0436 (12)0.1119 (19)−0.0089 (10)0.0550 (14)0.0108 (12)
O40.0582 (13)0.0610 (13)0.0958 (17)0.0082 (10)0.0448 (12)0.0052 (12)
N10.0541 (14)0.0254 (11)0.0716 (16)−0.0034 (10)0.0363 (13)−0.0040 (10)
N20.0497 (15)0.0443 (14)0.0687 (17)0.0010 (12)0.0273 (13)0.0050 (12)
C10.0406 (15)0.0224 (12)0.0464 (16)0.0003 (10)0.0156 (12)−0.0020 (10)
C20.0416 (15)0.0307 (13)0.0447 (15)−0.0026 (11)0.0160 (13)−0.0013 (11)
C30.0464 (16)0.0261 (12)0.0584 (17)0.0005 (11)0.0216 (14)−0.0032 (12)
C40.0461 (16)0.0333 (15)0.0586 (18)0.0050 (12)0.0212 (14)−0.0029 (12)
C50.0414 (15)0.0366 (15)0.0497 (16)−0.0023 (11)0.0190 (13)0.0030 (12)
C60.0438 (15)0.0288 (13)0.0502 (16)−0.0012 (11)0.0137 (13)−0.0003 (11)
C70.0467 (16)0.0264 (14)0.0494 (16)−0.0001 (11)0.0141 (14)−0.0006 (12)
C80.069 (2)0.0257 (14)0.076 (2)−0.0092 (12)0.0404 (16)−0.0070 (13)

Geometric parameters (Å, °)

O1—C71.230 (4)C1—C61.380 (4)
O2—C71.319 (3)C2—C31.423 (3)
O3—N21.227 (3)C3—C41.357 (4)
O4—N21.228 (3)C4—C51.388 (3)
O2—H20.8200C5—C61.373 (4)
N1—C81.443 (3)C3—H30.9300
N1—C21.326 (3)C4—H40.9300
N2—C51.437 (3)C6—H60.9300
N1—H10.8600C8—H8A0.9600
C1—C71.466 (3)C8—H8B0.9600
C1—C21.430 (3)C8—H8C0.9600
C7—O2—H2109.00N2—C5—C6119.7 (2)
C2—N1—C8124.3 (2)C1—C6—C5121.1 (2)
O3—N2—C5119.2 (2)O1—C7—O2121.4 (2)
O4—N2—C5118.1 (2)O1—C7—C1124.5 (2)
O3—N2—O4122.7 (2)O2—C7—C1114.2 (2)
C2—N1—H1118.00C2—C3—H3119.00
C8—N1—H1118.00C4—C3—H3119.00
C6—C1—C7119.8 (2)C3—C4—H4120.00
C2—C1—C6119.5 (2)C5—C4—H4120.00
C2—C1—C7120.7 (2)C1—C6—H6119.00
N1—C2—C3119.9 (2)C5—C6—H6119.00
N1—C2—C1122.7 (2)N1—C8—H8A109.00
C1—C2—C3117.4 (2)N1—C8—H8B109.00
C2—C3—C4121.5 (2)N1—C8—H8C109.00
C3—C4—C5119.9 (2)H8A—C8—H8B109.00
C4—C5—C6120.6 (2)H8A—C8—H8C110.00
N2—C5—C4119.6 (2)H8B—C8—H8C109.00
C8—N1—C2—C1175.8 (3)C2—C1—C7—O14.1 (4)
C8—N1—C2—C3−5.1 (4)C2—C1—C7—O2−175.9 (2)
O3—N2—C5—C4176.8 (3)C6—C1—C7—O1−178.0 (2)
O3—N2—C5—C6−2.0 (4)C6—C1—C7—O22.0 (4)
O4—N2—C5—C4−1.9 (4)N1—C2—C3—C4−179.3 (2)
O4—N2—C5—C6179.4 (3)C1—C2—C3—C4−0.1 (4)
C6—C1—C2—N1179.6 (2)C2—C3—C4—C5−0.3 (4)
C6—C1—C2—C30.4 (4)C3—C4—C5—N2−178.4 (2)
C7—C1—C2—N1−2.5 (4)C3—C4—C5—C60.4 (4)
C7—C1—C2—C3178.4 (2)N2—C5—C6—C1178.7 (2)
C2—C1—C6—C5−0.4 (4)C4—C5—C6—C10.0 (4)
C7—C1—C6—C5−178.3 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1···O10.862.032.694 (3)134
N1—H1···O4i0.862.523.165 (3)133
O2—H2···O1ii0.821.862.679 (3)177

Symmetry codes: (i) x−1, −y+1/2, z+1/2; (ii) −x+1, −y+1, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB5463).

References

  • Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl.34, 1555–1573.
  • Blank, A., Hellstern, V., Schuster, D., Hartmann, M., Matthée, A. K., Burhenne, J., Haefeli, W. E. & Mikus, G. (2009). Clin. Infect. Dis.48, 1787–1789. [PubMed]
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  • Bruker (2007). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
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  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
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  • Kamal, A., Vijaya, B. E., Janaki, R. M., Dastagiri, D., Surendranadha, R. J., Viswanath, A., Sultana, F., Pal-Bhadra, M., Srivastava, H. K., Narahari, S. G., Juvekar, A. & Zingde, S. (2010). Bioorg. Med. Chem.18, 526–542. [PubMed]
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