7-Chloro-5-(chloro­meth­yl)pyrazolo­[1,5-a]pyrimidine-3-carbonitrile

Abstract

All non-H atoms of the title compound, C₈H₄Cl₂N₄, are essentially coplanar, with an r.m.s. deviation of 0.011 Å. In the crystal, weak C—H⋯N hydrogen bonds link the mol­ecules into infinite sheets parallel to the bc plane.

Related literature  

For details of the synthesis, see: Li et al. (2006 ▶). For applications of pyrazolo­[1,5-a]pyrimidines as pharmacophores or building blocks in anti-tumor drug design, see: Li et al. (2006 ▶); Di Grandi et al. (2009 ▶); Powell et al. (2007 ▶); Gopalsamy et al. (2005 ▶).

Experimental  

Crystal data  

• C₈H₄Cl₂N₄

• M _r = 227.05

• Monoclinic,

• a = 4.9817 (4) Å

• b = 18.4025 (15) Å

• c = 10.1526 (9) Å

• β = 95.924 (1)°

• V = 925.78 (13) ų

• Z = 4

• Mo Kα radiation

• μ = 0.66 mm⁻¹

• T = 301 K

• 0.60 × 0.48 × 0.20 mm

Data collection  

• Bruker SMART APEX CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.693, T _max = 0.879

• 5429 measured reflections

• 2111 independent reflections

• 1749 reflections with I > 2σ(I)

• R _int = 0.017

Refinement  

• R[F ² > 2σ(F ²)] = 0.038

• wR(F ²) = 0.104

• S = 1.04

• 2111 reflections

• 127 parameters

• H-atom parameters constrained

• Δρ_max = 0.46 e Å⁻³

• Δρ_min = −0.53 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; 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: SHELXTL.

Supplementary Material

Supplementary material file. DOI: 10.1107/S160053681201166X/im2361Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯N2i	0.93	2.50	3.337 (3)	150
C2—H2⋯N2ii	0.93	2.70	3.515 (3)	146

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

Pyrazolo[1,5-a]pyrimidines are widely applied as important pharmacophores or building blocks in anti-tumor drug design (Di Grandi et al., 2009; Powell et al., 2007; Gopalsamy et al., 2005; Li et al., 2006). Thus, the synthesis of the title compound may lead to the development of further pyrazolo[1,5-a]pyrimidine derivatives as new anti-tumor drugs. Here we report the crystal structure of the title compound.

The molecular structure of the title compound is shown in Fig. 1. The complete molecule is essentially planar, except the H atoms of the methylene group. Each molecule acts as a donor and a acceptor of weak intermolecular C—H···N hydrogen-bond interactions linking the molecules into infinite sheets (Fig. 2).

Experimental

The title compound can prepared by the reaction of 5-(chloromethyl)-7-hydroxypyrazolo[1,5-a]pyrimidine-3-carbonitrile with phosphorus oxychloride (Li et al., 2006). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the crude product in ethyl acetate at ambient temperature.

Refinement

All H atoms attached to C atoms were fixed geometrically and treated as riding with C—H = 0.93 Å (CH) and C—H = 0.97 Å (CH₂) with U_iso(H) =1.2U_eq(C).

Figures

Fig. 1.

Molecular structure of the title compound showing displacement ellipsoids at the 45% probability level.

Fig. 2.

Packing diagram of the title compound, viewed along the a axis. Dashed lines indicate hydrogen bonds.

Crystal data

C8H4Cl2N4	F(000) = 456
Mr = 227.05	Dx = 1.629 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2237 reflections
a = 4.9817 (4) Å	θ = 3.9–27.6°
b = 18.4025 (15) Å	µ = 0.66 mm−1
c = 10.1526 (9) Å	T = 301 K
β = 95.924 (1)°	Block, red
V = 925.78 (13) Å3	0.60 × 0.48 × 0.20 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	2111 independent reflections
Radiation source: fine-focus sealed tube	1749 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
phi and ω scans	θmax = 27.6°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −6→6
Tmin = 0.693, Tmax = 0.879	k = −13→23
5429 measured reflections	l = −12→12

Refinement

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.104	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.050P)2 + 0.3703P] where P = (Fo2 + 2Fc2)/3
2111 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.46 e Å−3
0 restraints	Δρmin = −0.53 e Å−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.32935 (9)	0.26419 (3)	0.40816 (5)	0.04533 (17)
Cl2	0.73176 (14)	0.03358 (3)	0.13931 (8)	0.0784 (3)
N1	0.9223 (3)	0.23861 (8)	0.10690 (15)	0.0376 (3)
N2	1.2065 (4)	0.41634 (10)	−0.0585 (2)	0.0636 (5)
N3	0.5932 (4)	0.38077 (9)	0.26671 (18)	0.0503 (4)
N4	0.6551 (3)	0.31043 (8)	0.24035 (15)	0.0374 (3)
C1	0.5553 (4)	0.25052 (10)	0.29599 (18)	0.0363 (4)
C2	0.6391 (4)	0.18420 (10)	0.25839 (18)	0.0390 (4)
H2	0.5762	0.1420	0.2952	0.047*
C3	0.8249 (4)	0.18073 (10)	0.16175 (18)	0.0378 (4)
C4	0.9331 (5)	0.10975 (11)	0.1153 (2)	0.0554 (6)
H4A	1.1109	0.1018	0.1615	0.066*
H4B	0.9540	0.1138	0.0216	0.066*
C5	0.8380 (3)	0.30370 (10)	0.14617 (17)	0.0352 (4)
C6	0.8930 (4)	0.37484 (10)	0.11144 (19)	0.0423 (4)
C7	1.0677 (4)	0.39787 (10)	0.0175 (2)	0.0473 (5)
C8	0.7377 (5)	0.41835 (11)	0.1879 (2)	0.0520 (5)
H8	0.7362	0.4688	0.1837	0.062*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0409 (3)	0.0559 (3)	0.0418 (3)	−0.0012 (2)	0.01678 (19)	−0.0018 (2)
Cl2	0.0764 (4)	0.0456 (3)	0.1169 (6)	−0.0135 (3)	0.0270 (4)	−0.0184 (3)
N1	0.0376 (8)	0.0389 (8)	0.0378 (8)	0.0000 (6)	0.0108 (6)	0.0019 (6)
N2	0.0747 (13)	0.0502 (11)	0.0710 (13)	−0.0039 (10)	0.0321 (11)	0.0098 (10)
N3	0.0591 (11)	0.0374 (9)	0.0574 (10)	0.0019 (8)	0.0213 (8)	−0.0043 (8)
N4	0.0381 (8)	0.0379 (8)	0.0377 (8)	−0.0003 (6)	0.0110 (6)	−0.0009 (6)
C1	0.0323 (8)	0.0449 (10)	0.0328 (8)	−0.0023 (7)	0.0089 (7)	0.0012 (7)
C2	0.0403 (9)	0.0381 (10)	0.0398 (9)	−0.0032 (8)	0.0099 (8)	0.0035 (8)
C3	0.0403 (9)	0.0364 (9)	0.0376 (9)	−0.0009 (7)	0.0075 (7)	0.0007 (7)
C4	0.0654 (14)	0.0379 (11)	0.0676 (14)	0.0002 (10)	0.0292 (11)	−0.0003 (10)
C5	0.0333 (8)	0.0391 (9)	0.0341 (9)	−0.0023 (7)	0.0078 (7)	0.0007 (7)
C6	0.0458 (10)	0.0368 (10)	0.0458 (10)	−0.0045 (8)	0.0114 (8)	0.0033 (8)
C7	0.0549 (12)	0.0360 (10)	0.0527 (12)	−0.0045 (9)	0.0137 (10)	0.0047 (9)
C8	0.0621 (13)	0.0350 (10)	0.0612 (13)	−0.0022 (9)	0.0177 (11)	−0.0011 (9)

Geometric parameters (Å, º)

Cl1—C1	1.7006 (18)	C2—C3	1.418 (2)
Cl2—C4	1.755 (2)	C2—H2	0.9300
N1—C3	1.318 (2)	C3—C4	1.507 (3)
N1—C5	1.343 (2)	C4—H4A	0.9700
N2—C7	1.139 (3)	C4—H4B	0.9700
N3—C8	1.325 (3)	C5—C6	1.390 (3)
N3—N4	1.364 (2)	C6—C8	1.402 (3)
N4—C1	1.356 (2)	C6—C7	1.421 (3)
N4—C5	1.393 (2)	C8—H8	0.9300
C1—C2	1.357 (3)
C3—N1—C5	117.09 (15)	C3—C4—H4A	108.6
C8—N3—N4	103.25 (16)	Cl2—C4—H4A	108.6
C1—N4—N3	126.15 (15)	C3—C4—H4B	108.6
C1—N4—C5	120.50 (15)	Cl2—C4—H4B	108.6
N3—N4—C5	113.35 (15)	H4A—C4—H4B	107.5
N4—C1—C2	118.49 (16)	N1—C5—C6	133.52 (16)
N4—C1—Cl1	117.07 (14)	N1—C5—N4	121.99 (15)
C2—C1—Cl1	124.44 (14)	C6—C5—N4	104.50 (15)
C1—C2—C3	118.48 (16)	C5—C6—C8	105.24 (17)
C1—C2—H2	120.8	C5—C6—C7	126.97 (18)
C3—C2—H2	120.8	C8—C6—C7	127.79 (19)
N1—C3—C2	123.45 (17)	N2—C7—C6	179.6 (3)
N1—C3—C4	114.14 (16)	N3—C8—C6	113.67 (19)
C2—C3—C4	122.40 (16)	N3—C8—H8	123.2
C3—C4—Cl2	114.86 (15)	C6—C8—H8	123.2
C8—N3—N4—C1	−179.43 (19)	C3—N1—C5—C6	−179.6 (2)
C8—N3—N4—C5	0.3 (2)	C3—N1—C5—N4	−0.2 (3)
N3—N4—C1—C2	−179.90 (18)	C1—N4—C5—N1	0.0 (3)
C5—N4—C1—C2	0.4 (3)	N3—N4—C5—N1	−179.71 (17)
N3—N4—C1—Cl1	0.6 (3)	C1—N4—C5—C6	179.58 (16)
C5—N4—C1—Cl1	−179.05 (13)	N3—N4—C5—C6	−0.1 (2)
N4—C1—C2—C3	−0.6 (3)	N1—C5—C6—C8	179.4 (2)
Cl1—C1—C2—C3	178.78 (14)	N4—C5—C6—C8	0.0 (2)
C5—N1—C3—C2	−0.1 (3)	N1—C5—C6—C7	0.0 (4)
C5—N1—C3—C4	−178.66 (18)	N4—C5—C6—C7	−179.5 (2)
C1—C2—C3—N1	0.5 (3)	N4—N3—C8—C6	−0.3 (3)
C1—C2—C3—C4	178.98 (19)	C5—C6—C8—N3	0.2 (3)
N1—C3—C4—Cl2	−159.03 (16)	C7—C6—C8—N3	179.7 (2)
C2—C3—C4—Cl2	22.4 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···N2i	0.93	2.50	3.337 (3)	150
C2—H2···N2ii	0.93	2.70	3.515 (3)	146

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