2-Methyl-6-nitro-2H-indazole

Long, L.; Liu, B.-N.; Liu, M.; Liu, D.-K.

doi:10.1107/S1600536811019374

organic compounds

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ISSN: 2056-9890

Volume 67| Part 6| June 2011| Page o1546

doi:10.1107/S1600536811019374

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2-Methyl-6-nitro-2H-indazole

Li Long,^a Bing-Ni Liu,^b ^* Mo Liu ^b and Deng-Ke Liu ^b

^aSchool of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300160, People's Republic of China, and ^bTianjin Institute of Pharmaceutical Research, Tianjin, 300193, People's Republic of China
^*Correspondence e-mail: liudk@tjipr.com

(Received 18 May 2011; accepted 23 May 2011; online 28 May 2011)

In the title compound, C₈H₇N₃O₂, the molecular skeleton is almost planar with a maximum deviation of 0.0484 (9) Å for the methyl C atom. In the crystal, weak intermolecular C—H⋯N and C—H⋯O hydrogen bonds help to establish the packing.

Related literature

For the synthesis, see: Sorbera et al. (2006 ); Balardi et al. (1997 ). For related structures, see: Qi et al. (2010 ); Chen et al. (2009 ). For applications of indazole derivatives, see, for example: Li et al. (2008 ).

Experimental

Crystal data

C₈H₇N₃O₂
M_r = 177.17
Monoclinic, P 2₁ /c
a = 3.793 (3) Å
b = 12.200 (8) Å
c = 16.675 (11) Å
β = 95.722 (9)°
V = 767.7 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 113 K
0.40 × 0.20 × 0.10 mm

Data collection

Rigaku Saturn724 CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ) T_min = 0.956, T_max = 0.989
7726 measured reflections
1802 independent reflections
1317 reflections with I > 2σ(I)
R_int = 0.039

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.092
S = 1.03
1802 reflections
119 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯N2ⁱ	0.95	2.52	3.446 (2)	164
C7—H7⋯O2ⁱⁱ	0.95	2.56	3.500 (2)	169
C8—H8A⋯O2ⁱⁱⁱ	0.98	2.61	3.549 (2)	161
C8—H8B⋯O1ⁱⁱ	0.98	2.51	3.491 (2)	174
Symmetry codes: (i) -x, -y, -z+2; (ii) $[x+1, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) -x+1, -y, -z+2.

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2005).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811019374/cv5096sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811019374/cv5096Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811019374/cv5096Isup3.cdx

Supporting information file. DOI: 10.1107/S1600536811019374/cv5096Isup4.cml

checkCIF report

Comment top

Some derivatives of indazole are important intermediates in the synthesis of drugs (Li et al. 2008). Herewith we report the crystal structure of the tile compound (I), which is an intermediate in the synthesis of the antitumor agent pazopanib.

In (I) (Fig. 1), the bond lengths and angles are normal and comparable with those reported for related compounds (Qi et al., 2010; Chen et al., 2009). Rings N2/N3/C7/C6/C1 and C1—C6 are almost coplanar forming a dihedral angle 1.08 (7) °. The indazole ring system is almost planar with the maximal deviation of 0.0118 (7) Å for atom N3. Nitro group is twisted at 0.93 (16)° from the plane of the attached indazole ring system.

In the crystal structure, weak intermolecular C—H···N and C—H···O hydrogen bonds (Table 1) help to establish the packing.

Related literature top

For the synthesis, see: Sorbera et al. (2006); Balardi et al. (1997). For related structures, see: Qi et al. (2010); Chen et al. (2009). For applications of indazole derivatives, see, for example: Li et al. (2008).

Experimental top

The title compound was prepared according to Sorbera et al. (2006) and Balardi et al. (1997). 6-Nitro-1H-indazole (2 g) was dissolved in regurgitant dichloromethane (30 ml), then dimethyl sulfate (1.7 ml) and dimethyl sulfoxide (2 ml) were introduced. The mixture was heated to reflux and stayed for 12 h. The reaction mixture was washed with saturated sodium bicarbonate (10 ml) and then extracted with dichloromethane (20 ml), dried with sodium sulfate and evaporated, to give yellow solid (78% yield). Crystals suitable for X-ray analysis were obtained by slow evaporation of a dichloromethane.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2005).

Figures top

Fig. 1. The molecular structure of (I), with the atom-numbering scheme and 50% probability displacement ellipsoids.

2-Methyl-6-nitro-2H-indazole top

Crystal data top

C₈H₇N₃O₂	F(000) = 368
M_r = 177.17	D_x = 1.533 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2636 reflections
a = 3.793 (3) Å	θ = 2.1–28.0°
b = 12.200 (8) Å	µ = 0.12 mm⁻¹
c = 16.675 (11) Å	T = 113 K
β = 95.722 (9)°	Prism, colourless
V = 767.7 (9) Å³	0.40 × 0.20 × 0.10 mm
Z = 4

Data collection top

Rigaku Saturn724 CCD diffractometer	1802 independent reflections
Radiation source: rotating anode	1317 reflections with I > 2σ(I)
Multilayer monochromator	R_int = 0.039
Detector resolution: 14.22 pixels mm^-1	θ_max = 27.9°, θ_min = 2.1°
ω and ϕ scans	h = −4→4
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −15→16
T_min = 0.956, T_max = 0.989	l = −21→21
7726 measured reflections

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.092	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.05P)²] where P = (F_o² + 2F_c²)/3
1802 reflections	(Δ/σ)_max = 0.001
119 parameters	Δρ_max = 0.28 e Å⁻³
0 restraints	Δρ_min = −0.23 e Å⁻³

Crystal data top

C₈H₇N₃O₂	V = 767.7 (9) Å³
M_r = 177.17	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 3.793 (3) Å	µ = 0.12 mm⁻¹
b = 12.200 (8) Å	T = 113 K
c = 16.675 (11) Å	0.40 × 0.20 × 0.10 mm
β = 95.722 (9)°

Data collection top

Rigaku Saturn724 CCD diffractometer	1802 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	1317 reflections with I > 2σ(I)
T_min = 0.956, T_max = 0.989	R_int = 0.039
7726 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.092	H-atom parameters constrained
S = 1.03	Δρ_max = 0.28 e Å⁻³
1802 reflections	Δρ_min = −0.23 e Å⁻³
119 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
O1	0.0001 (2)	0.40192 (7)	1.13521 (6)	0.0330 (3)
O2	−0.1008 (2)	0.23042 (7)	1.15673 (5)	0.0285 (2)
N1	0.0034 (2)	0.30444 (8)	1.11496 (6)	0.0204 (2)
N2	0.2860 (2)	0.04933 (8)	0.90394 (6)	0.0191 (2)
N3	0.4265 (2)	0.07413 (8)	0.83460 (6)	0.0189 (2)
C1	0.2577 (3)	0.14834 (9)	0.93942 (7)	0.0164 (3)
C2	0.1284 (3)	0.16936 (9)	1.01433 (7)	0.0172 (3)
H2	0.0426	0.1128	1.0463	0.021*
C3	0.1351 (3)	0.27717 (9)	1.03783 (7)	0.0172 (3)
C4	0.2556 (3)	0.36516 (9)	0.99200 (7)	0.0197 (3)
H4	0.2521	0.4380	1.0120	0.024*
C5	0.3767 (3)	0.34458 (9)	0.91902 (7)	0.0202 (3)
H5	0.4565	0.4026	0.8874	0.024*
C6	0.3805 (3)	0.23462 (9)	0.89161 (7)	0.0175 (3)
C7	0.4868 (3)	0.18162 (9)	0.82402 (7)	0.0197 (3)
H7	0.5827	0.2147	0.7794	0.024*
C8	0.5084 (3)	−0.01456 (9)	0.78106 (8)	0.0225 (3)
H8A	0.6589	−0.0687	0.8114	0.034*
H8B	0.6335	0.0150	0.7372	0.034*
H8C	0.2879	−0.0497	0.7586	0.034*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0491 (6)	0.0212 (5)	0.0301 (5)	0.0001 (4)	0.0114 (4)	−0.0077 (4)
O2	0.0399 (5)	0.0249 (5)	0.0227 (5)	−0.0030 (4)	0.0126 (4)	0.0002 (4)
N1	0.0211 (5)	0.0207 (5)	0.0195 (5)	0.0007 (4)	0.0026 (4)	−0.0017 (4)
N2	0.0233 (5)	0.0198 (5)	0.0149 (5)	−0.0002 (4)	0.0058 (4)	0.0000 (4)
N3	0.0200 (5)	0.0216 (5)	0.0155 (5)	0.0003 (4)	0.0040 (4)	0.0004 (4)
C1	0.0147 (5)	0.0172 (5)	0.0171 (6)	0.0000 (4)	0.0004 (4)	0.0013 (4)
C2	0.0182 (6)	0.0172 (5)	0.0163 (6)	−0.0002 (4)	0.0021 (5)	0.0013 (4)
C3	0.0155 (6)	0.0203 (6)	0.0158 (6)	0.0016 (4)	0.0018 (5)	−0.0004 (5)
C4	0.0194 (6)	0.0161 (6)	0.0235 (6)	−0.0009 (4)	0.0010 (5)	0.0008 (5)
C5	0.0194 (6)	0.0189 (6)	0.0222 (6)	−0.0015 (5)	0.0026 (5)	0.0046 (5)
C6	0.0151 (6)	0.0208 (6)	0.0163 (6)	−0.0002 (4)	0.0008 (4)	0.0027 (5)
C7	0.0193 (6)	0.0218 (6)	0.0185 (6)	−0.0013 (5)	0.0036 (5)	0.0033 (5)
C8	0.0262 (6)	0.0234 (6)	0.0190 (6)	0.0016 (5)	0.0073 (5)	−0.0029 (5)

Geometric parameters (Å, º) top

O1—N1	1.2367 (14)	C3—C4	1.4194 (17)
O2—N1	1.2294 (14)	C4—C5	1.3662 (19)
N1—C3	1.4639 (17)	C4—H4	0.9500
N2—C1	1.3539 (16)	C5—C6	1.4178 (17)
N2—N3	1.3547 (15)	C5—H5	0.9500
N3—C7	1.3459 (17)	C6—C7	1.3934 (18)
N3—C8	1.4559 (16)	C7—H7	0.9500
C1—C2	1.4102 (18)	C8—H8A	0.9800
C1—C6	1.4265 (17)	C8—H8B	0.9800
C2—C3	1.3719 (17)	C8—H8C	0.9800
C2—H2	0.9500

O2—N1—O1	122.63 (11)	C5—C4—H4	120.2
O2—N1—C3	119.20 (10)	C3—C4—H4	120.2
O1—N1—C3	118.17 (10)	C4—C5—C6	118.44 (11)
C1—N2—N3	103.23 (10)	C4—C5—H5	120.8
C7—N3—N2	114.58 (10)	C6—C5—H5	120.8
C7—N3—C8	126.47 (11)	C7—C6—C5	135.47 (11)
N2—N3—C8	118.91 (10)	C7—C6—C1	104.27 (11)
N2—C1—C2	126.80 (10)	C5—C6—C1	120.25 (11)
N2—C1—C6	111.69 (11)	N3—C7—C6	106.23 (11)
C2—C1—C6	121.50 (11)	N3—C7—H7	126.9
C3—C2—C1	115.41 (10)	C6—C7—H7	126.9
C3—C2—H2	122.3	N3—C8—H8A	109.5
C1—C2—H2	122.3	N3—C8—H8B	109.5
C2—C3—C4	124.70 (12)	H8A—C8—H8B	109.5
C2—C3—N1	118.07 (10)	N3—C8—H8C	109.5
C4—C3—N1	117.22 (10)	H8A—C8—H8C	109.5
C5—C4—C3	119.69 (11)	H8B—C8—H8C	109.5

C1—N2—N3—C7	−0.23 (12)	N1—C3—C4—C5	−179.08 (10)
C1—N2—N3—C8	177.69 (9)	C3—C4—C5—C6	−0.52 (16)
N3—N2—C1—C2	−179.34 (10)	C4—C5—C6—C7	−178.43 (12)
N3—N2—C1—C6	0.13 (12)	C4—C5—C6—C1	0.46 (16)
N2—C1—C2—C3	178.46 (10)	N2—C1—C6—C7	0.01 (12)
C6—C1—C2—C3	−0.96 (15)	C2—C1—C6—C7	179.51 (10)
C1—C2—C3—C4	0.92 (16)	N2—C1—C6—C5	−179.19 (9)
C1—C2—C3—N1	179.81 (9)	C2—C1—C6—C5	0.31 (16)
O2—N1—C3—C2	1.59 (15)	N2—N3—C7—C6	0.24 (12)
O1—N1—C3—C2	−178.04 (10)	C8—N3—C7—C6	−177.50 (10)
O2—N1—C3—C4	−179.44 (9)	C5—C6—C7—N3	178.87 (12)
O1—N1—C3—C4	0.93 (14)	C1—C6—C7—N3	−0.14 (11)
C2—C3—C4—C5	−0.19 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N2ⁱ	0.95	2.52	3.446 (2)	164
C7—H7···O2ⁱⁱ	0.95	2.56	3.500 (2)	169
C8—H8A···O2ⁱⁱⁱ	0.98	2.61	3.549 (2)	161
C8—H8B···O1ⁱⁱ	0.98	2.51	3.491 (2)	174

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

Experimental details

Crystal data
Chemical formula	C₈H₇N₃O₂
M_r	177.17
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	113
a, b, c (Å)	3.793 (3), 12.200 (8), 16.675 (11)
β (°)	95.722 (9)
V (Å³)	767.7 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.12
Crystal size (mm)	0.40 × 0.20 × 0.10

Data collection
Diffractometer	Rigaku Saturn724 CCD diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku/MSC, 2005)
T_min, T_max	0.956, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	7726, 1802, 1317
R_int	0.039
(sin θ/λ)_max (Å⁻¹)	0.659

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.092, 1.03
No. of reflections	1802
No. of parameters	119
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.28, −0.23

Computer programs: CrystalClear (Rigaku/MSC, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), CrystalStructure (Rigaku/MSC, 2005).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N2ⁱ	0.95	2.52	3.446 (2)	164
C7—H7···O2ⁱⁱ	0.95	2.56	3.500 (2)	169
C8—H8A···O2ⁱⁱⁱ	0.98	2.61	3.549 (2)	161
C8—H8B···O1ⁱⁱ	0.98	2.51	3.491 (2)	174

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

Acknowledgements

The authors thank Mr Hai-Bin Song of Nankai University for the X-ray crystallographic determination and for helpful suggestions.

References

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