1-(2-Chloro­eth­yl)-1H-pyrazolo­[3,4-d]pyrimidin-4(5H)-one

Abstract

In the title compound, C₇H₇ClN₄O, the pyrazolo­pyrimidine ring is essentially planar, the r.m.s. deviation of the fitted atoms being 0.0071 Å. The crystal structure features strong N—H⋯O hydrogen bonds and further consolidated by weak C—H⋯O, C—H⋯N and C—H⋯Cl inter­actions.

Related literature  

For the biological activity of pyrazolo­pyrimidines, see: Carraro et al. (2006 ▶). For a related structure, see: Dolzhenko et al. (2009 ▶). For the graph-set analysis of hydrogen bonding, see: Bernstein et al. (1995 ▶).

Experimental  

Crystal data  

• C₇H₇ClN₄O

• M _r = 198.61

• Monoclinic,

• a = 4.6448 (1) Å

• b = 8.0792 (1) Å

• c = 22.7335 (4) Å

• β = 93.554 (1)°

• V = 851.46 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.41 mm⁻¹

• T = 296 K

• 0.18 × 0.16 × 0.16 mm

Data collection  

• Bruker SMART APEX CCD detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.930, T _max = 0.937

• 7660 measured reflections

• 1548 independent reflections

• 1353 reflections with I > 2σ(I)

• R _int = 0.023

Refinement  

• R[F ² > 2σ(F ²)] = 0.035

• wR(F ²) = 0.100

• S = 0.87

• 1548 reflections

• 118 parameters

• H-atom parameters constrained

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.37 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; 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 CAMERON (Watkin et al., 1996 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812025184/pv2552Isup3.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
N1—H1⋯O1i	0.86	1.96	2.810 (2)	170
C5—H5A⋯N4ii	0.93	2.79	3.676 (2)	160
C2—H2A⋯Cl1iii	0.97	2.84	3.779 (2)	164
C2—H2B⋯N2iv	0.97	2.59	3.463 (2)	150
C3—H3⋯O1v	0.93	2.35	3.254 (2)	163

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .

supplementary crystallographic information

Comment

Pyrazolo[3,4-d]pyrimidines are purine analogues which exhibit a number of pharmacological properties such as antitryproliferative (Carraro et al., 2006).

In the title compound (Fig. 1), the fused pyrazolopyrimidine ring is substituted with 2-chloro-ethyl group on one side and the oxo group on the other side. The pyrazolopyrimidine ring is planar with the maximum deviation from the mean statistical plane being 0.0115 (14) Å for C3. The cis orientation of 2-chloro-ethyl group with respect to the C2—N2 bond is described by the torsion angle N2—C2—N3—C3, -2.204 (4)°.

The crystal structure is stabilized by some interesting features that comprise of intermolecular N—H···O, C—H···O, C—H···N and C—H···Cl interactions (Fig. 2 and Tab. 1). The C—H···O and the N—H···O interactions result in centrosymmetric head-to-head dimers corresponding to the graph set R²₂(10) and R²₂(8) motif (Bernstein et al., 1995). There are two types of C—H···N interactions, one of which forms a helix, the other forms sheets along the crystallographic b-axis. The C—H···Cl intermolecular interaction result in one dimensional molecular chain along b-axis. The bond lengths and bond angles in the title molecule agree very well with the corresponding bond distances and bond angles reported in a closely related compound (Dolzhenko et al., 2009).

Experimental

A mixture of 5-amino-1-(2-chloro-ethyl)-1H-pyrazole-4-carbonitrile (1 g, 5.8 mmol) and formic acid (15 ml) was heated under reflux for 10 h. The excess of formic acid was removed under reduced pressure and the solid separated was washed with water and recrystallized from ethanol. (Yield = 0.86 g, 75% and m.p. = 470–472 K).

Refinement

The H atoms were placed at calculated positions in the riding model approximation with N—H = 0.86 Å and C—H = 0.93, and 0.97 Å for aryl and methylene H-atoms respectively, with U_iso(H) = 1.2U_eq(N/C).

Figures

Fig. 1.

The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

Fig. 2.

A view of the intermolecular hydrogen bonds (dotted lines) in the crystal structure of the title compound. H atoms non participating in H-bonding were ommitted for clarity.

Crystal data

C7H7ClN4O	F(000) = 416
Mr = 198.61	Dx = 1.565 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1548 reflections
a = 4.6448 (1) Å	θ = 1.8–25.2°
b = 8.0792 (1) Å	µ = 0.41 mm−1
c = 22.7335 (4) Å	T = 296 K
β = 93.554 (1)°	Block, yellow
V = 851.46 (3) Å3	0.18 × 0.16 × 0.16 mm
Z = 4

Data collection

Bruker SMART APEX CCD detector diffractometer	1548 independent reflections
Radiation source: fine-focus sealed tube	1353 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ω scans	θmax = 25.2°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −5→5
Tmin = 0.930, Tmax = 0.937	k = −9→9
7660 measured reflections	l = −27→25

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.100	H-atom parameters constrained
S = 0.87	w = 1/[σ2(Fo2) + (0.0642P)2 + 0.5291P] where P = (Fo2 + 2Fc2)/3
1548 reflections	(Δ/σ)max = 0.001
118 parameters	Δρmax = 0.19 e Å−3
0 restraints	Δρmin = −0.37 e Å−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	0.89765 (12)	0.64259 (8)	0.72864 (2)	0.0600 (2)
O1	0.5103 (3)	0.78930 (17)	0.99906 (6)	0.0516 (4)
N1	0.7733 (3)	0.95763 (18)	0.94256 (6)	0.0381 (4)
H1	0.7021	1.0429	0.9590	0.046*
N2	1.0887 (3)	0.86963 (19)	0.87124 (7)	0.0396 (4)
N3	1.0967 (3)	0.57267 (18)	0.86397 (6)	0.0376 (4)
N4	0.9763 (3)	0.43809 (19)	0.88974 (7)	0.0434 (4)
C5	0.9640 (4)	0.9842 (2)	0.90068 (8)	0.0401 (4)
H5A	1.0092	1.0935	0.8924	0.048*
C6	1.0057 (4)	0.7151 (2)	0.88711 (7)	0.0331 (4)
C1	1.2904 (4)	0.5504 (3)	0.81692 (8)	0.0418 (4)
H1A	1.4385	0.4711	0.8295	0.050*
H1B	1.3848	0.6548	0.8096	0.050*
C2	1.1398 (4)	0.4907 (2)	0.76054 (8)	0.0442 (5)
H2A	1.0330	0.3907	0.7683	0.053*
H2B	1.2826	0.4635	0.7327	0.053*
C4	0.6848 (4)	0.8026 (2)	0.96076 (7)	0.0371 (4)
C7	0.8174 (4)	0.6729 (2)	0.92974 (7)	0.0349 (4)
C3	0.8092 (4)	0.4993 (2)	0.92932 (8)	0.0424 (4)
H3	0.7002	0.4356	0.9538	0.051*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0545 (3)	0.0640 (4)	0.0607 (4)	0.0019 (2)	−0.0027 (3)	0.0011 (3)
O1	0.0692 (9)	0.0403 (8)	0.0488 (8)	−0.0011 (6)	0.0335 (7)	−0.0006 (6)
N1	0.0486 (8)	0.0314 (8)	0.0355 (8)	0.0000 (6)	0.0122 (6)	−0.0036 (6)
N2	0.0475 (9)	0.0357 (8)	0.0370 (8)	−0.0044 (7)	0.0137 (7)	−0.0006 (6)
N3	0.0437 (8)	0.0351 (8)	0.0354 (8)	0.0002 (6)	0.0121 (6)	−0.0014 (6)
N4	0.0550 (9)	0.0326 (8)	0.0436 (9)	0.0000 (7)	0.0117 (7)	0.0026 (7)
C5	0.0489 (10)	0.0352 (10)	0.0372 (9)	−0.0061 (8)	0.0098 (8)	0.0021 (8)
C6	0.0360 (9)	0.0343 (9)	0.0295 (8)	−0.0008 (7)	0.0060 (7)	−0.0005 (7)
C1	0.0397 (9)	0.0451 (11)	0.0418 (10)	0.0050 (8)	0.0132 (8)	−0.0037 (8)
C2	0.0505 (11)	0.0395 (11)	0.0442 (10)	0.0004 (8)	0.0159 (8)	−0.0060 (8)
C4	0.0452 (10)	0.0365 (10)	0.0304 (9)	−0.0030 (8)	0.0088 (7)	−0.0002 (7)
C7	0.0413 (9)	0.0347 (9)	0.0293 (8)	−0.0019 (7)	0.0076 (7)	0.0006 (7)
C3	0.0528 (11)	0.0364 (10)	0.0393 (10)	−0.0025 (8)	0.0141 (8)	0.0033 (8)

Geometric parameters (Å, º)

Cl1—C2	1.788 (2)	C5—H5A	0.9300
O1—C4	1.231 (2)	C6—C7	1.388 (2)
N1—C5	1.357 (2)	C1—C2	1.501 (3)
N1—C4	1.389 (2)	C1—H1A	0.9700
N1—H1	0.8600	C1—H1B	0.9700
N2—C5	1.299 (2)	C2—H2A	0.9700
N2—C6	1.362 (2)	C2—H2B	0.9700
N3—C6	1.344 (2)	C4—C7	1.424 (2)
N3—N4	1.371 (2)	C7—C3	1.403 (3)
N3—C1	1.451 (2)	C3—H3	0.9300
N4—C3	1.320 (2)
C5—N1—C4	124.71 (15)	C2—C1—H1B	109.0
C5—N1—H1	117.6	H1A—C1—H1B	107.8
C4—N1—H1	117.6	C1—C2—Cl1	112.00 (14)
C5—N2—C6	111.97 (15)	C1—C2—H2A	109.2
C6—N3—N4	111.42 (13)	Cl1—C2—H2A	109.2
C6—N3—C1	128.26 (15)	C1—C2—H2B	109.2
N4—N3—C1	120.30 (15)	Cl1—C2—H2B	109.2
C3—N4—N3	105.48 (15)	H2A—C2—H2B	107.9
N2—C5—N1	125.45 (17)	O1—C4—N1	120.63 (16)
N2—C5—H5A	117.3	O1—C4—C7	127.58 (17)
N1—C5—H5A	117.3	N1—C4—C7	111.79 (14)
N3—C6—N2	125.45 (15)	C6—C7—C3	105.00 (16)
N3—C6—C7	106.86 (15)	C6—C7—C4	118.38 (16)
N2—C6—C7	127.68 (16)	C3—C7—C4	136.61 (17)
N3—C1—C2	113.08 (15)	N4—C3—C7	111.23 (16)
N3—C1—H1A	109.0	N4—C3—H3	124.4
C2—C1—H1A	109.0	C7—C3—H3	124.4
N3—C1—H1B	109.0
C6—N3—N4—C3	−0.1 (2)	C5—N1—C4—O1	−179.89 (18)
C1—N3—N4—C3	−178.72 (16)	C5—N1—C4—C7	−0.4 (2)
C6—N2—C5—N1	0.1 (3)	N3—C6—C7—C3	0.2 (2)
C4—N1—C5—N2	0.7 (3)	N2—C6—C7—C3	−179.13 (18)
N4—N3—C6—N2	179.28 (17)	N3—C6—C7—C4	−179.02 (15)
C1—N3—C6—N2	−2.2 (3)	N2—C6—C7—C4	1.6 (3)
N4—N3—C6—C7	−0.1 (2)	O1—C4—C7—C6	178.81 (19)
C1—N3—C6—C7	178.40 (17)	N1—C4—C7—C6	−0.6 (2)
C5—N2—C6—N3	179.47 (17)	O1—C4—C7—C3	−0.1 (4)
C5—N2—C6—C7	−1.3 (3)	N1—C4—C7—C3	−179.6 (2)
C6—N3—C1—C2	−108.1 (2)	N3—N4—C3—C7	0.2 (2)
N4—N3—C1—C2	70.3 (2)	C6—C7—C3—N4	−0.3 (2)
N3—C1—C2—Cl1	66.78 (19)	C4—C7—C3—N4	178.7 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.86	1.96	2.810 (2)	170
C5—H5A···N4ii	0.93	2.79	3.676 (2)	160
C2—H2A···Cl1iii	0.97	2.84	3.779 (2)	164
C2—H2B···N2iv	0.97	2.59	3.463 (2)	150
C3—H3···O1v	0.93	2.35	3.254 (2)	163

Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) x, y+1, z; (iii) −x+3/2, y−1/2, −z+3/2; (iv) −x+5/2, y−1/2, −z+3/2; (v) −x+1, −y+1, −z+2.