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ISSN: 2056-9890

3-Iodo-1H-pyrazolo­[3,4-b]pyridine

aCardinal Tien College of Healthcare & Management, Taipei, 231, Taiwan, bInstitute of Chemistry, Academia Sinica, Nankang, Taipei, Taiwan, and cDepartment of Chemistry, National Taiwan University, Taipei, Taiwan
*Correspondence e-mail: pshuang@ctcn.edu.tw

Edited by M. Zeller, Youngstown State University, USA (Received 6 March 2014; accepted 4 May 2014; online 10 May 2014)

The title compound, C6H4IN3, is essentially planar, with a dihedral angle of 0.82 (3)° between the planes of the pyridine and pyrazole rings. In the crystal, pairs of mol­ecules are connected into inversion dimers through N—H⋯N hydrogen bonds. C—I⋯N halogen bonds link the dimers into zigzag chains parallel to the b-axis direction. The packing also features ππ stacking inter­actions along (110) with inter­planar distances of 3.292 (1) and 3.343 (1) Å, and centroid–centroid distances of 3.308 (1) and 3.430 (1) Å.

Related literature

For the production of anti­tumor agents, see: Huang et al. (2007[Huang, S., Lin, R., Yu, Y., Lu, Y., Connolly, P. J., Chiu, G., Li, S., Emanuel, S. L. & Middleton, S. A. (2007). Bioorg. Med. Chem. Lett. 17, 1243-1245.]); Ye et al. (2009[Ye, Q., Cao, J., Zhou, X., Lv, D., He, Q., Yang, B. & Hu, Y. (2009). Bioorg. Med. Chem. Lett. 17, 4763-4772.]). For a related structure, see: Huang et al. (2013[Huang, P.-H., Wen, Y.-S. & Shen, J.-Y. (2013). Acta Cryst. E69, o674.]).

[Scheme 1]

Experimental

Crystal data
  • C6H4IN3

  • Mr = 245.02

  • Monoclinic, C 2/c

  • a = 10.7999 (13) Å

  • b = 7.7939 (9) Å

  • c = 17.406 (2) Å

  • β = 101.748 (2)°

  • V = 1434.5 (3) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 4.38 mm−1

  • T = 150 K

  • 0.35 × 0.32 × 0.25 mm

Data collection
  • Bruker SMART APEX CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 1996[Bruker (1996). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.309, Tmax = 0.407

  • 5315 measured reflections

  • 1470 independent reflections

  • 1423 reflections with I > 2σ(I)

  • Rint = 0.022

Refinement
  • R[F2 > 2σ(F2)] = 0.017

  • wR(F2) = 0.040

  • S = 1.13

  • 1470 reflections

  • 91 parameters

  • 26 restraints

  • H-atom parameters constrained

  • Δρmax = 0.40 e Å−3

  • Δρmin = −0.46 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 2.09 2.926 (3) 159
C6—I1⋯N3ii 2.076 (2) 3.013 (2) 5.056 (3) 166.72 (7)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Comment top

The title compound has been shown to be a precursor for the production of anticancer drugs (Huang et al., 2007; Ye et al., 2009). The molecular structure is shown in Figure 1. The dihedral angle between the pyridine and the pyrazole rings is 0.82 (3)°. (Huang et al., 2013) As shown in Fig.1, N—H···N H-bonds connect molecules into centrosymmetric dimers. The molecules connected the H-bonds are arranged in a parallel but non-coplanar fashion, with the planes of the two molcecules being about 0.67 Å apart. C—I···N halogen bonds create zig zag chains parallel to the b axis direction, Fig. 2. Packing is also facilitated through π···π stacking interactions along (1 1 0) with interplanar distances of 3.292 (1) and 3.343 (1) Å, and centroid to centroid distances of 3.308 (1) and 3.430 (1) Å (Fig 3.). Molecules in the crystal structure are thus connected through N—H···N hydrogen bonding interactions, through a C—I···N halogen bond as well as π···π stacking interactions that help to stabilize the crystal structure.

Related literature top

For the production of antitumor agents, see: Huang et al. (2007); Ye et al. (2009). For related structures, see: Huang et al. (2013).

Experimental top

The compound was synthesized by the following procedure (Ye et al., 2009). Iodine (18.7 g, 73.6 mmol) was added to a solution of 1H-pyrazolo[3,4-b]pyridine (3.5 g, 29.4 mmol) in DMF (50 ml), followed by KOH (6.6 g, 118.0 mmol). The mixture was stirred at room temperature for 2 h. After that, it was poured into brine and extracted with ethyl acetate and the organic extract was washed with brine and aqueous Na2SO4, dried and concentrated in vacuum. The residue was purified by recrystallization in CH2Cl2 and hexane to give a white solid (6.3 g, 87.5%). Crystals suitable for X-ray diffraction were grown from a CH2Cl2 solution layered with hexane at room temperature. 1H NMR (CDCl3, 400 MHz): 13.18 (br, 1 H), 8.64 (dd, 1 H, J = 4.8, 1.6 Hz), 7.89 (dd, 1 H, J = 8.4, 1.6 Hz), 7.25–7.22 (m, 1H). Mass spectrum: m/e245 (M+), calcd. (245.02).

Refinement top

H atoms were located in difference map but were positioned with idealized geometry and refined isotropic with Uiso(H) = 1.2Ueq(C,N).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. The centrosymmetric dimer molecular structures of the title compound with labeling and displacement ellipsoids drawn at the 30% probability level. H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. Packing diagram for title compound, viewed along the b axis. H atom have been omitted for clarity.
[Figure 3] Fig. 3. In the crystal, there are significant π···π stacking interactions between molecules.
3-Iodo-1H-pyrazolo[3,4-b]pyridine top
Crystal data top
C6H4IN3F(000) = 912
Mr = 245.02Dx = 2.269 Mg m3
Dm = 2.269 Mg m3
Dm measured by not measured
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 10.7999 (13) ÅCell parameters from 4550 reflections
b = 7.7939 (9) Åθ = 2.4–27.5°
c = 17.406 (2) ŵ = 4.38 mm1
β = 101.748 (2)°T = 150 K
V = 1434.5 (3) Å3Block, colorless
Z = 80.35 × 0.32 × 0.25 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
1470 independent reflections
Radiation source: fine-focus sealed tube1423 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
ω scansθmax = 26.4°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 1996)
h = 1413
Tmin = 0.309, Tmax = 0.407k = 109
5315 measured reflectionsl = 2222
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)] = 0.017Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.040H-atom parameters constrained
S = 1.13 w = 1/[σ2(Fo2) + (0.0156P)2 + 1.9173P]
where P = (Fo2 + 2Fc2)/3
1470 reflections(Δ/σ)max = 0.003
91 parametersΔρmax = 0.40 e Å3
26 restraintsΔρmin = 0.46 e Å3
Crystal data top
C6H4IN3V = 1434.5 (3) Å3
Mr = 245.02Z = 8
Monoclinic, C2/cMo Kα radiation
a = 10.7999 (13) ŵ = 4.38 mm1
b = 7.7939 (9) ÅT = 150 K
c = 17.406 (2) Å0.35 × 0.32 × 0.25 mm
β = 101.748 (2)°
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
1470 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1996)
1423 reflections with I > 2σ(I)
Tmin = 0.309, Tmax = 0.407Rint = 0.022
5315 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.01726 restraints
wR(F2) = 0.040H-atom parameters constrained
S = 1.13Δρmax = 0.40 e Å3
1470 reflectionsΔρmin = 0.46 e Å3
91 parameters
Special details top

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
I10.23044 (2)1.04283 (2)0.29263 (2)0.02252 (7)
N10.46725 (18)0.6969 (3)0.56007 (11)0.0202 (4)
N20.44327 (18)0.6579 (3)0.42063 (11)0.0196 (4)
H2A0.48690.56220.42190.023*
N30.38503 (19)0.7396 (3)0.35341 (11)0.0201 (4)
C10.4368 (2)0.8083 (3)0.61183 (13)0.0226 (5)
H10.46410.78220.66600.027*
C20.3682 (2)0.9594 (3)0.59272 (15)0.0249 (5)
H20.35171.03250.63320.030*
C30.3242 (2)1.0027 (3)0.51533 (15)0.0223 (5)
H30.27581.10380.50100.027*
C40.3539 (2)0.8915 (3)0.45868 (13)0.0177 (4)
C50.4249 (2)0.7441 (3)0.48502 (13)0.0178 (4)
C60.3326 (2)0.8785 (3)0.37596 (13)0.0189 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.02567 (11)0.01896 (10)0.02189 (10)0.00157 (6)0.00242 (7)0.00504 (6)
N10.0215 (10)0.0196 (10)0.0186 (9)0.0028 (8)0.0020 (8)0.0012 (8)
N20.0222 (10)0.0173 (10)0.0184 (9)0.0042 (8)0.0020 (8)0.0004 (7)
N30.0229 (10)0.0192 (10)0.0174 (9)0.0007 (8)0.0022 (8)0.0019 (8)
C10.0264 (13)0.0240 (12)0.0174 (10)0.0075 (10)0.0043 (9)0.0015 (9)
C20.0281 (14)0.0234 (13)0.0252 (12)0.0062 (10)0.0105 (10)0.0064 (10)
C30.0241 (13)0.0159 (11)0.0287 (12)0.0020 (10)0.0097 (10)0.0022 (9)
C40.0181 (11)0.0138 (11)0.0218 (11)0.0036 (9)0.0051 (9)0.0011 (9)
C50.0171 (11)0.0160 (11)0.0200 (11)0.0037 (9)0.0031 (8)0.0009 (8)
C60.0187 (11)0.0168 (11)0.0205 (11)0.0006 (9)0.0023 (9)0.0026 (9)
Geometric parameters (Å, º) top
I1—C62.076 (2)C1—H10.9500
N1—C11.339 (3)C2—C31.376 (4)
N1—C51.345 (3)C2—H20.9500
N2—C51.356 (3)C3—C41.398 (3)
N2—N31.368 (3)C3—H30.9500
N2—H2A0.8800C4—C51.405 (3)
N3—C61.318 (3)C4—C61.415 (3)
C1—C21.396 (4)
C1—N1—C5113.2 (2)C2—C3—H3121.5
C5—N2—N3110.93 (18)C4—C3—H3121.5
C5—N2—H2A124.5C3—C4—C5117.7 (2)
N3—N2—H2A124.5C3—C4—C6138.5 (2)
C6—N3—N2106.15 (18)C5—C4—C6103.79 (19)
N1—C1—C2125.3 (2)N1—C5—N2126.1 (2)
N1—C1—H1117.4N1—C5—C4126.6 (2)
C2—C1—H1117.4N2—C5—C4107.31 (19)
C3—C2—C1120.1 (2)N3—C6—C4111.8 (2)
C3—C2—H2120.0N3—C6—I1119.88 (16)
C1—C2—H2120.0C4—C6—I1128.30 (17)
C2—C3—C4117.1 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···N1i0.882.092.926 (3)159
C6—I1···N3ii2.08 (1)3.01 (1)5.056 (3)167 (1)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1/2, y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···N1i0.882.092.926 (3)158.9
C6—I1···N3ii2.076 (2)3.013 (2)5.056 (3)166.72 (7)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

This work was partially supported by the Instrumentation Center of National Taiwan University, and by Cardinal Tien College of Healthcare & Management.

References

First citationBruker (1996). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationHuang, S., Lin, R., Yu, Y., Lu, Y., Connolly, P. J., Chiu, G., Li, S., Emanuel, S. L. & Middleton, S. A. (2007). Bioorg. Med. Chem. Lett. 17, 1243–1245.  Web of Science CrossRef PubMed CAS Google Scholar
First citationHuang, P.-H., Wen, Y.-S. & Shen, J.-Y. (2013). Acta Cryst. E69, o674.  CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYe, Q., Cao, J., Zhou, X., Lv, D., He, Q., Yang, B. & Hu, Y. (2009). Bioorg. Med. Chem. Lett. 17, 4763–4772.  Web of Science CrossRef CAS Google Scholar

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ISSN: 2056-9890
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