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ISSN: 2056-9890

4-Methyl-3-nitro­pyridin-2-amine

aInstitute of Chemistry, University of the Punjab, Lahore, Pakistan, bUniversity of Sargodha, Department of Physics, Sargodha, Pakistan, and cApplied Chemistry Research Center, PCSIR Laboratories complex, Lahore 54600, Pakistan
*Correspondence e-mail: dmntahir_uos@yahoo.com

(Received 11 June 2009; accepted 12 June 2009; online 20 June 2009)

In the title compound, C6H7N3O2, the dihedral angle between the nitro group and the pyridine ring is 15.5 (3)° and an intra­molecular N—H⋯O hydrogen bond occurs. In the crystal, inversion dimers linked by two N—H⋯N hydrogen bonds occur, resulting in R22(8) rings. The packing is stabilized by aromatic ππ stacking [centroid–centroid distance = 3.5666 (15) Å] and a short N—O⋯π contact is seen.

Related literature

For a related structure, see: Kvick & Noordik (1977[Kvick, Å. & Noordik, J. (1977). Acta Cryst. B33, 2862-2866.]). For graph-set notation, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • C6H7N3O2

  • Mr = 153.15

  • Monoclinic, P 21 /n

  • a = 7.3776 (6) Å

  • b = 12.8673 (11) Å

  • c = 7.3884 (6) Å

  • β = 104.364 (4)°

  • V = 679.45 (10) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 296 K

  • 0.25 × 0.10 × 0.08 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.985, Tmax = 0.992

  • 7483 measured reflections

  • 1677 independent reflections

  • 759 reflections with I > 2σ(I)

  • Rint = 0.055

Refinement
  • R[F2 > 2σ(F2)] = 0.056

  • wR(F2) = 0.173

  • S = 1.00

  • 1677 reflections

  • 107 parameters

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

  • Δρmax = 0.39 e Å−3

  • Δρmin = −0.32 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2A⋯N1i 0.88 (3) 2.17 (4) 3.045 (4) 174 (3)
N2—H2B⋯O1 0.85 (3) 2.01 (3) 2.612 (4) 127 (2)
N3—O2⋯Cg1ii 1.20 (1) 3.27 (1) 3.681 (12) 100 (1)
Symmetry codes: (i) -x+1, -y, -z; (ii) -x+2, -y, -z+1. Cg1 is the centroid of the pyridine ring.

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]) and PLATON.

Supporting information


Comment top

Pyridines form a very important class of heterocyclic compounds. In it are included various vitamins, enzymes, pharmaceuticals, dyes, agrochemicals and other products. The title compound (I), (Fig. 1) is nitro substituted 2-Amino-4-methylpyridine.

The crystal structure of (II) 2-Amino-4-methylpyridine (Kvick & Noordik, 1977) has been reported. In (I), the pyridine ring A (C1—C5/N1) is planar with Rms deviation of 0.0135 Å. The amino N-atom and the methyl C-atom deviates from the plane of ring A by -0.0551 (37) Å and -0.044 (4) Å, respectively. The dihedral angle between ring A and nitro group B (O1/N3/O2) is 15.53 (27)°. The title compound consists of dimers due to inversion related intermolecular H-bonds of N–H···N type forming ring motifs R22(8) (Bernstein et al., 1995). The interamoleculr H-bond of N–H···O type completes R11(6) ring motif (Fig. 2). The molecules are stabilized due to ππ-interactions with centroid to centroid distance of 3.5666 (15) Å [CgA···CgAi: symmetry code i = 2 - x, -y, -z] and N–O···π interactions (Table 1).

Related literature top

For a related structure, see: Kvick & Noordik (1977). For graph-set notation, see: Bernstein et al. (1995). Cg1 is the centroid of the pyridine ring.

Experimental top

2-Amino-4-picoline (1.1 g, 0.01 mol) was dissolved in 10 ml of concentrated nitric and sulfuric acid (1:1) and cooled to 278 K. The mixture was left overnight and the resultant nitramino product was further treated with 5 ml of conc. sulfuric acid at room temperature for 3 h and poured over 250 g of crushed ice. The precipitates obtained were collected by filtration and subjected to steam distillation. The title compound was obtained as yellow needles of (I) on cooling the distillate to room temperature.

Refinement top

The coordinates of the H-atoms of the NH2 group were located in a difference map and refined. The other H-atoms were positioned geometrically (C—H = 0.93—0.96 Å) and refined as riding with Uiso(H) = 1.2Ueq(C, N).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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 PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. View of (I) with displacement ellipsoids drawn at the 50% probability level. H-atoms are shown by small spheres of arbitrary radii. Intermolecular H-bond is shown by dotted lines.
[Figure 2] Fig. 2. The partial packing of (I), which shows that molecules form dimers.
4-Methyl-3-nitropyridin-2-amine top
Crystal data top
C6H7N3O2F(000) = 320
Mr = 153.15Dx = 1.497 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1677 reflections
a = 7.3776 (6) Åθ = 3.2–28.3°
b = 12.8673 (11) ŵ = 0.12 mm1
c = 7.3884 (6) ÅT = 296 K
β = 104.364 (4)°Needle, yellow
V = 679.45 (10) Å30.25 × 0.10 × 0.08 mm
Z = 4
Data collection top
Bruker Kappa APEXII CCD
diffractometer
1677 independent reflections
Radiation source: fine-focus sealed tube759 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.055
Detector resolution: 7.40 pixels mm-1θmax = 28.3°, θmin = 3.2°
ω scansh = 99
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
k = 1717
Tmin = 0.985, Tmax = 0.992l = 99
7483 measured reflections
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)] = 0.056Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.173H atoms treated by a mixture of independent and constrained refinement
S = 1.00 w = 1/[σ2(Fo2) + (0.0745P)2 + 0.0769P]
where P = (Fo2 + 2Fc2)/3
1677 reflections(Δ/σ)max < 0.001
107 parametersΔρmax = 0.39 e Å3
0 restraintsΔρmin = 0.32 e Å3
Crystal data top
C6H7N3O2V = 679.45 (10) Å3
Mr = 153.15Z = 4
Monoclinic, P21/nMo Kα radiation
a = 7.3776 (6) ŵ = 0.12 mm1
b = 12.8673 (11) ÅT = 296 K
c = 7.3884 (6) Å0.25 × 0.10 × 0.08 mm
β = 104.364 (4)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
1677 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
759 reflections with I > 2σ(I)
Tmin = 0.985, Tmax = 0.992Rint = 0.055
7483 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0560 restraints
wR(F2) = 0.173H atoms treated by a mixture of independent and constrained refinement
S = 1.00Δρmax = 0.39 e Å3
1677 reflectionsΔρmin = 0.32 e Å3
107 parameters
Special details top

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 e.s.d.'s 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) top
xyzUiso*/Ueq
O10.9915 (3)0.20091 (18)0.2978 (3)0.0860 (10)
O21.2249 (3)0.11801 (19)0.4483 (4)0.0904 (10)
N10.7197 (3)0.06783 (18)0.0831 (3)0.0426 (8)
N20.6845 (4)0.1039 (2)0.1310 (3)0.0529 (9)
N31.0759 (3)0.11908 (19)0.3358 (3)0.0475 (9)
C10.8004 (4)0.0221 (2)0.1552 (3)0.0386 (8)
C20.9935 (3)0.0238 (2)0.2507 (3)0.0378 (9)
C31.1041 (3)0.0656 (2)0.2608 (3)0.0405 (9)
C41.0135 (4)0.1542 (2)0.1803 (4)0.0480 (10)
C50.8246 (4)0.1511 (2)0.0979 (4)0.0472 (10)
C61.3108 (4)0.0719 (3)0.3480 (4)0.0555 (10)
H2A0.570 (5)0.089 (2)0.066 (4)0.0635*
H2B0.730 (4)0.164 (2)0.156 (4)0.0635*
H41.079860.215820.181700.0576*
H50.767020.212750.048990.0566*
H6A1.357380.137850.318880.0666*
H6B1.373650.017080.299730.0666*
H6C1.333340.064750.481070.0666*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0667 (16)0.0497 (16)0.127 (2)0.0025 (12)0.0035 (14)0.0240 (14)
O20.0609 (15)0.0759 (19)0.110 (2)0.0105 (13)0.0247 (14)0.0200 (14)
N10.0373 (12)0.0424 (14)0.0475 (13)0.0041 (11)0.0096 (10)0.0006 (11)
N20.0399 (13)0.0506 (17)0.0639 (16)0.0020 (13)0.0048 (12)0.0097 (14)
N30.0416 (14)0.0502 (17)0.0506 (14)0.0091 (12)0.0110 (12)0.0076 (12)
C10.0355 (14)0.0427 (16)0.0394 (14)0.0019 (13)0.0126 (11)0.0016 (12)
C20.0356 (15)0.0404 (16)0.0378 (14)0.0070 (12)0.0101 (11)0.0004 (12)
C30.0361 (14)0.0500 (18)0.0354 (14)0.0038 (13)0.0090 (11)0.0046 (12)
C40.0493 (18)0.0399 (17)0.0547 (17)0.0042 (14)0.0126 (14)0.0032 (14)
C50.0495 (18)0.0421 (17)0.0492 (16)0.0105 (14)0.0110 (13)0.0001 (13)
C60.0391 (16)0.066 (2)0.0589 (18)0.0051 (14)0.0077 (13)0.0058 (16)
Geometric parameters (Å, º) top
O1—N31.220 (3)C2—C31.402 (4)
O2—N31.203 (3)C3—C41.380 (4)
N1—C11.349 (3)C3—C61.503 (4)
N1—C51.310 (4)C4—C51.376 (4)
N2—C11.340 (4)C4—H40.9300
N3—C21.442 (3)C5—H50.9300
N2—H2B0.85 (3)C6—H6A0.9600
N2—H2A0.88 (3)C6—H6B0.9600
C1—C21.425 (4)C6—H6C0.9600
C1—N1—C5118.4 (2)C2—C3—C4116.2 (2)
O1—N3—O2119.7 (2)C4—C3—C6118.2 (3)
O1—N3—C2119.9 (2)C3—C4—C5119.7 (2)
O2—N3—C2120.4 (2)N1—C5—C4125.0 (3)
H2A—N2—H2B126 (3)C3—C4—H4120.00
C1—N2—H2A113.3 (18)C5—C4—H4120.00
C1—N2—H2B119 (2)N1—C5—H5118.00
N1—C1—N2114.6 (3)C4—C5—H5118.00
N1—C1—C2119.9 (2)C3—C6—H6A109.00
N2—C1—C2125.5 (2)C3—C6—H6B109.00
N3—C2—C1119.4 (2)C3—C6—H6C109.00
N3—C2—C3119.9 (2)H6A—C6—H6B109.00
C1—C2—C3120.8 (2)H6A—C6—H6C109.00
C2—C3—C6125.6 (2)H6B—C6—H6C109.00
C5—N1—C1—N2178.7 (2)N2—C1—C2—N32.1 (4)
C5—N1—C1—C22.3 (4)N2—C1—C2—C3177.2 (2)
C1—N1—C5—C40.8 (4)N3—C2—C3—C4178.3 (2)
O1—N3—C2—C113.3 (3)N3—C2—C3—C62.8 (4)
O1—N3—C2—C3166.0 (2)C1—C2—C3—C42.4 (3)
O2—N3—C2—C1164.5 (2)C1—C2—C3—C6176.4 (2)
O2—N3—C2—C316.2 (4)C2—C3—C4—C50.5 (4)
N1—C1—C2—N3176.7 (2)C6—C3—C4—C5179.5 (3)
N1—C1—C2—C34.0 (3)C3—C4—C5—N12.3 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···N1i0.88 (3)2.17 (4)3.045 (4)174 (3)
N2—H2B···O10.85 (3)2.01 (3)2.612 (4)127 (2)
N3—O2···Cg1ii1.20 (1)3.27 (1)3.681 (12)100 (1)
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z+1.

Experimental details

Crystal data
Chemical formulaC6H7N3O2
Mr153.15
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)7.3776 (6), 12.8673 (11), 7.3884 (6)
β (°) 104.364 (4)
V3)679.45 (10)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.25 × 0.10 × 0.08
Data collection
DiffractometerBruker Kappa APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.985, 0.992
No. of measured, independent and
observed [I > 2σ(I)] reflections
7483, 1677, 759
Rint0.055
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.056, 0.173, 1.00
No. of reflections1677
No. of parameters107
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.39, 0.32

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···N1i0.88 (3)2.17 (4)3.045 (4)174 (3)
N2—H2B···O10.85 (3)2.01 (3)2.612 (4)127 (2)
N3—O2···Cg1ii1.203 (3)3.2743 (3)3.681 (12)100.16 (17)
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z+1.
 

Acknowledgements

The authors acknowledge the Higher Education Commission, Islamabad, Pakistan, and Bana International, Karachi, Pakistan, for funding the purchase of the diffractometer at GCU, Lahore and for technical support, respectively.

References

First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationBruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationKvick, Å. & Noordik, J. (1977). Acta Cryst. B33, 2862–2866.  CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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