3-Iodo-1H-pyrazolo­[3,4-b]pyridine

Huang, P.-H.; Wen, Y.-S.; Shen, J.-Y.

doi:10.1107/S1600536814010009

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 70| Part 6| June 2014| Page o650

doi:10.1107/S1600536814010009

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3-Iodo-1H-pyrazolo[3,4-b]pyridine

Ping-Hsin Huang,^a ^* Yuh-Sheng Wen ^b and Jiun-Yi Shen ^c

^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 π–π 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.

CCDC reference: 1000735

Related literature

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

Experimental

Crystal data

C₆H₄IN₃
M_r = 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 ) T_min = 0.309, T_max = 0.407
5315 measured reflections
1470 independent reflections
1423 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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 ); 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).

Supporting information

CCDC reference: 1000735

Crystal structure: contains datablocks ic14830, I. DOI: 10.1107/S1600536814010009/zl2581sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536814010009/zl2581Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536814010009/zl2581Isup3.cml

checkCIF report

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).

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

	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.
	Fig. 2. Packing diagram for title compound, viewed along the b axis. H atom have been omitted for clarity.
	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

C₆H₄IN₃	F(000) = 912
M_r = 245.02	D_x = 2.269 Mg m⁻³ D_m = 2.269 Mg m⁻³ D_m measured by not measured
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.7999 (13) Å	Cell parameters from 4550 reflections
b = 7.7939 (9) Å	θ = 2.4–27.5°
c = 17.406 (2) Å	µ = 4.38 mm⁻¹
β = 101.748 (2)°	T = 150 K
V = 1434.5 (3) Å³	Block, colorless
Z = 8	0.35 × 0.32 × 0.25 mm

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1470 independent reflections
Radiation source: fine-focus sealed tube	1423 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.022
ω scans	θ_max = 26.4°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 1996)	h = −14→13
T_min = 0.309, T_max = 0.407	k = −10→9
5315 measured reflections	l = −22→22

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)] = 0.017	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.040	H-atom parameters constrained
S = 1.13	w = 1/[σ²(F_o²) + (0.0156P)² + 1.9173P] where P = (F_o² + 2F_c²)/3
1470 reflections	(Δ/σ)_max = 0.003
91 parameters	Δρ_max = 0.40 e Å⁻³
26 restraints	Δρ_min = −0.46 e Å⁻³

Crystal data top

C₆H₄IN₃	V = 1434.5 (3) Å³
M_r = 245.02	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 10.7999 (13) Å	µ = 4.38 mm⁻¹
b = 7.7939 (9) Å	T = 150 K
c = 17.406 (2) Å	0.35 × 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)
T_min = 0.309, T_max = 0.407	R_int = 0.022
5315 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.017	26 restraints
wR(F²) = 0.040	H-atom parameters constrained
S = 1.13	Δρ_max = 0.40 e Å⁻³
1470 reflections	Δρ_min = −0.46 e Å⁻³
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

	x	y	z	U_iso*/U_eq
I1	0.23044 (2)	1.04283 (2)	0.29263 (2)	0.02252 (7)
N1	0.46725 (18)	0.6969 (3)	0.56007 (11)	0.0202 (4)
N2	0.44327 (18)	0.6579 (3)	0.42063 (11)	0.0196 (4)
H2A	0.4869	0.5622	0.4219	0.023*
N3	0.38503 (19)	0.7396 (3)	0.35341 (11)	0.0201 (4)
C1	0.4368 (2)	0.8083 (3)	0.61183 (13)	0.0226 (5)
H1	0.4641	0.7822	0.6660	0.027*
C2	0.3682 (2)	0.9594 (3)	0.59272 (15)	0.0249 (5)
H2	0.3517	1.0325	0.6332	0.030*
C3	0.3242 (2)	1.0027 (3)	0.51533 (15)	0.0223 (5)
H3	0.2758	1.1038	0.5010	0.027*
C4	0.3539 (2)	0.8915 (3)	0.45868 (13)	0.0177 (4)
C5	0.4249 (2)	0.7441 (3)	0.48502 (13)	0.0178 (4)
C6	0.3326 (2)	0.8785 (3)	0.37596 (13)	0.0189 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
I1	0.02567 (11)	0.01896 (10)	0.02189 (10)	0.00157 (6)	0.00242 (7)	0.00504 (6)
N1	0.0215 (10)	0.0196 (10)	0.0186 (9)	−0.0028 (8)	0.0020 (8)	0.0012 (8)
N2	0.0222 (10)	0.0173 (10)	0.0184 (9)	0.0042 (8)	0.0020 (8)	0.0004 (7)
N3	0.0229 (10)	0.0192 (10)	0.0174 (9)	−0.0007 (8)	0.0022 (8)	0.0019 (8)
C1	0.0264 (13)	0.0240 (12)	0.0174 (10)	−0.0075 (10)	0.0043 (9)	−0.0015 (9)
C2	0.0281 (14)	0.0234 (13)	0.0252 (12)	−0.0062 (10)	0.0105 (10)	−0.0064 (10)
C3	0.0241 (13)	0.0159 (11)	0.0287 (12)	−0.0020 (10)	0.0097 (10)	−0.0022 (9)
C4	0.0181 (11)	0.0138 (11)	0.0218 (11)	−0.0036 (9)	0.0051 (9)	0.0011 (9)
C5	0.0171 (11)	0.0160 (11)	0.0200 (11)	−0.0037 (9)	0.0031 (8)	−0.0009 (8)
C6	0.0187 (11)	0.0168 (11)	0.0205 (11)	−0.0006 (9)	0.0023 (9)	0.0026 (9)

Geometric parameters (Å, º) top

I1—C6	2.076 (2)	C1—H1	0.9500
N1—C1	1.339 (3)	C2—C3	1.376 (4)
N1—C5	1.345 (3)	C2—H2	0.9500
N2—C5	1.356 (3)	C3—C4	1.398 (3)
N2—N3	1.368 (3)	C3—H3	0.9500
N2—H2A	0.8800	C4—C5	1.405 (3)
N3—C6	1.318 (3)	C4—C6	1.415 (3)
C1—C2	1.396 (4)

C1—N1—C5	113.2 (2)	C2—C3—H3	121.5
C5—N2—N3	110.93 (18)	C4—C3—H3	121.5
C5—N2—H2A	124.5	C3—C4—C5	117.7 (2)
N3—N2—H2A	124.5	C3—C4—C6	138.5 (2)
C6—N3—N2	106.15 (18)	C5—C4—C6	103.79 (19)
N1—C1—C2	125.3 (2)	N1—C5—N2	126.1 (2)
N1—C1—H1	117.4	N1—C5—C4	126.6 (2)
C2—C1—H1	117.4	N2—C5—C4	107.31 (19)
C3—C2—C1	120.1 (2)	N3—C6—C4	111.8 (2)
C3—C2—H2	120.0	N3—C6—I1	119.88 (16)
C1—C2—H2	120.0	C4—C6—I1	128.30 (17)
C2—C3—C4	117.1 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1ⁱ	0.88	2.09	2.926 (3)	159
C6—I1···N3ⁱⁱ	2.08 (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···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1ⁱ	0.88	2.09	2.926 (3)	158.9
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+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

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