2,4-Dichloro­pyrimidine

Chen, Y.; Fang, Z.; Wei, P.

doi:10.1107/S1600536809019667

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page o1438

doi:10.1107/S1600536809019667

Open

access

2,4-Dichloropyrimidine

Yan Chen,^a Zheng Fang ^b ^* and Ping Wei ^a

^aCollege of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technolgy, Xinmofan Road No. 5 Nanjing, Nanjing 210009, People's Republic of China, and ^bSchool of Pharmaceutical Sciences, Nanjing University of Technolgy, Xinmofan Road No. 5 Nanjing, Nanjing 210009, People's Republic of China
^*Correspondence e-mail: fzcpu@163.com

(Received 21 May 2009; accepted 24 May 2009; online 29 May 2009)

The molecule of the title compound, C₄H₂Cl₂N₂, is almost planar [maximum deviation = 0.013 (3) Å for a Cl atom]. In the crystal structure, intermolecular C—H⋯N interactions link the molecules into chains.

Related literature

For a related structure, see: Bhasin et al. (2009 ). For bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₄H₂Cl₂N₂
M_r = 148.98
Monoclinic, P 2₁ /c
a = 7.5090 (15) Å
b = 10.776 (2) Å
c = 7.1980 (14) Å
β = 92.92 (3)°
V = 581.7 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.99 mm⁻¹
T = 294 K
0.30 × 0.20 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.755, T_max = 0.826
1223 measured reflections
1139 independent reflections
733 reflections with I > 2σ(I)
R_int = 0.084
3 standard reflections frequency: 120 min intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.069
wR(F²) = 0.180
S = 1.01
1139 reflections
73 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1B⋯N2ⁱ	0.93	2.62	3.548 (7)	174
Symmetry code: (i) $[-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809019667/hk2698sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809019667/hk2698Isup2.hkl

checkCIF report

Comment top

Some derivatives of pyrimidine are important chemical materials. We report herein the crystal structure of the title compound.

In the molecule of the title compound (Fig 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges. Ring A (N1/N2/C1-C4) is, of course, planar. Atoms Cl1 and Cl2 are 0.012 (3) and 0.013 (3) Å away from the ring plane, respectively. So, the molecule is planar.

In the crystal structure, intermolecular C-H···N interactions (Table 1) link the molecules into chains (Fig. 2), in which they may be effective in the stabilization of the structure.

Related literature top

For a related structure, see: Bhasin et al. (2009). For bond-length data, see: Allen et al. (1987).

Experimental top

For the preparation of the title compound, uracil (100 g, 0.82 mol) was dissolved in phosphorous oxychloride (400 ml) in a two-necked round-bottom flask (500 ml) equipped with a condenser. The solution was refluxed with stirring for 3.5 h at 383 K. The residual phosphorous oxychloride was removed in vacuo at 323 K, and the remaining oil was poured into ice (50 g) followed by extraction with chloroform (3 × 50 ml). The combined organic extract was washed with dilute sodium carbonate solution and dried over anhydrous sodium sulfate. The title compound was obtained by evaporation of solvent (Bhasin et al., 2009). Crystals suitable for X-ray analysis were obtained by slow evaporation of a methanol solution.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids at the 30% probability level.
	Fig. 2. A partial packing diagram of the title compound. Hydrogen bonds are shown as dashed lines.

2,4-Dichloropyrimidine top

Crystal data top

C₄H₂Cl₂N₂	F(000) = 296
M_r = 148.98	D_x = 1.701 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.5090 (15) Å	θ = 10–13°
b = 10.776 (2) Å	µ = 0.99 mm⁻¹
c = 7.1980 (14) Å	T = 294 K
β = 92.92 (3)°	Block, colorless
V = 581.7 (2) Å³	0.30 × 0.20 × 0.20 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	733 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.084
Graphite monochromator	θ_max = 26.0°, θ_min = 2.7°
ω/2θ scans	h = −9→0
Absorption correction: ψ scan (North et al., 1968)	k = 0→13
T_min = 0.755, T_max = 0.826	l = −8→8
1223 measured reflections	3 standard reflections every 120 min
1139 independent reflections	intensity decay: 1%

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)] = 0.069	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.180	H-atom parameters constrained
S = 1.01	w = 1/[σ²(F_o²) + (0.07P)² + 1.45P] where P = (F_o² + 2F_c²)/3
1139 reflections	(Δ/σ)_max < 0.001
73 parameters	Δρ_max = 0.39 e Å⁻³
0 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

C₄H₂Cl₂N₂	V = 581.7 (2) Å³
M_r = 148.98	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.5090 (15) Å	µ = 0.99 mm⁻¹
b = 10.776 (2) Å	T = 294 K
c = 7.1980 (14) Å	0.30 × 0.20 × 0.20 mm
β = 92.92 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	733 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.084
T_min = 0.755, T_max = 0.826	3 standard reflections every 120 min
1223 measured reflections	intensity decay: 1%
1139 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.069	0 restraints
wR(F²) = 0.180	H-atom parameters constrained
S = 1.01	Δρ_max = 0.39 e Å⁻³
1139 reflections	Δρ_min = −0.32 e Å⁻³
73 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
Cl1	0.5768 (2)	0.63809 (14)	0.0975 (2)	0.0762 (6)
Cl2	1.1679 (2)	0.83010 (16)	0.3510 (3)	0.0862 (7)
N1	0.6273 (6)	0.8744 (4)	0.0912 (7)	0.0612 (12)
N2	0.8628 (5)	0.7492 (4)	0.2211 (6)	0.0555 (11)
C1	0.8975 (7)	0.9681 (5)	0.2072 (8)	0.0652 (15)
H1B	0.9665	1.0384	0.2321	0.078*
C2	0.7272 (8)	0.9751 (5)	0.1252 (9)	0.0689 (16)
H2B	0.6808	1.0526	0.0927	0.083*
C3	0.7027 (6)	0.7699 (5)	0.1403 (7)	0.0485 (12)
C4	0.9577 (7)	0.8520 (5)	0.2490 (8)	0.0562 (14)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0693 (9)	0.0670 (10)	0.0897 (12)	−0.0184 (7)	−0.0222 (8)	−0.0065 (8)
Cl2	0.0581 (9)	0.0731 (11)	0.1233 (15)	−0.0074 (7)	−0.0370 (9)	−0.0038 (10)
N1	0.055 (3)	0.059 (3)	0.068 (3)	0.013 (2)	−0.009 (2)	0.002 (2)
N2	0.052 (2)	0.042 (2)	0.071 (3)	−0.0014 (18)	−0.017 (2)	−0.002 (2)
C1	0.070 (4)	0.042 (3)	0.081 (4)	0.000 (2)	−0.013 (3)	−0.007 (3)
C2	0.079 (4)	0.047 (3)	0.081 (4)	0.006 (3)	0.000 (3)	0.007 (3)
C3	0.045 (2)	0.056 (3)	0.044 (3)	0.005 (2)	−0.006 (2)	−0.007 (2)
C4	0.051 (3)	0.052 (3)	0.064 (3)	−0.002 (2)	−0.008 (3)	−0.005 (3)

Geometric parameters (Å, º) top

Cl1—C3	1.725 (5)	N2—C4	1.327 (6)
Cl2—C4	1.723 (5)	C1—C2	1.383 (8)
N1—C2	1.334 (7)	C1—C4	1.358 (7)
N1—C3	1.302 (6)	C1—H1B	0.9300
N2—C3	1.327 (6)	C2—H2B	0.9300

C3—N1—C2	114.9 (5)	C1—C2—H2B	118.9
C4—N2—C3	113.2 (4)	N1—C3—N2	129.5 (5)
C4—C1—C2	115.8 (5)	N1—C3—Cl1	115.9 (4)
C4—C1—H1B	122.1	N2—C3—Cl1	114.6 (4)
C2—C1—H1B	122.1	N2—C4—C1	124.4 (5)
N1—C2—C1	122.2 (5)	N2—C4—Cl2	115.0 (4)
N1—C2—H2B	118.9	C1—C4—Cl2	120.5 (4)

C3—N1—C2—C1	−0.2 (9)	C4—N2—C3—Cl1	178.8 (4)
C4—C1—C2—N1	0.7 (10)	C3—N2—C4—C1	2.5 (9)
C2—N1—C3—N2	1.0 (9)	C3—N2—C4—Cl2	−179.2 (4)
C2—N1—C3—Cl1	−179.9 (4)	C2—C1—C4—N2	−2.0 (10)
C4—N2—C3—N1	−2.0 (9)	C2—C1—C4—Cl2	179.8 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···N2ⁱ	0.93	2.62	3.548 (7)	174

Symmetry code: (i) −x+2, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₄H₂Cl₂N₂
M_r	148.98
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	294
a, b, c (Å)	7.5090 (15), 10.776 (2), 7.1980 (14)
β (°)	92.92 (3)
V (Å³)	581.7 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.99
Crystal size (mm)	0.30 × 0.20 × 0.20

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.755, 0.826
No. of measured, independent and observed [I > 2σ(I)] reflections	1223, 1139, 733
R_int	0.084
(sin θ/λ)_max (Å⁻¹)	0.618

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.069, 0.180, 1.01
No. of reflections	1139
No. of parameters	73
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.32

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···N2ⁱ	0.93	2.62	3.548 (7)	174

Symmetry code: (i) −x+2, y+1/2, −z+1/2.

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bhasin, K. K., Arora, E., Kaur, K., Kang, S. K., Gobel, M., Klapoetke, T. M. & Mehta, S. K. (2009). Tetrahedron, 65, 247–252. Web of Science CSD CrossRef CAS Google Scholar
Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar