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Acta Crystallogr Sect E Struct Rep Online. 2009 October 1; 65(Pt 10): o2356.
Published online 2009 September 5. doi:  10.1107/S1600536809034606
PMCID: PMC2970364

4,5-Dichloro-2H-1,3-oxazine-2,6(3H)-dione

Abstract

In the title compound, C4HCl2NO3, the essentially planar (maximum deviation = 0.023 Å for the ring O atom) mol­ecules form N—H(...)O hydrogen bonds between mol­ecules lying about inversion centers, forming eight-membered rings with an R 2 2(8) motif in graph-set notation.

Related literature

For synthetic background, see: Warren et al. (1975 [triangle]); Rehberg & Glass (1995 [triangle]). For related structures, see: Copley et al. (2005 [triangle]); Parrish, Leuschner et al. (2009 [triangle]); Parrish, Tivitmahaisoon et al. (2009 [triangle]). For graph-set notation in hydrogen bonding, see: Bernstein et al. (1994 [triangle]).

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Object name is e-65-o2356-scheme1.jpg

Experimental

Crystal data

  • C4HCl2NO3
  • M r = 181.96
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2356-efi1.jpg
  • a = 10.2290 (16) Å
  • b = 5.2549 (8) Å
  • c = 12.2766 (16) Å
  • β = 112.359 (11)°
  • V = 610.28 (16) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 1.00 mm−1
  • T = 293 K
  • 0.38 × 0.33 × 0.15 mm

Data collection

  • Siemens R3m/V diffractometer
  • Absorption correction: none
  • 1566 measured reflections
  • 1405 independent reflections
  • 1235 reflections with I > 2σ(I)
  • R int = 0.053
  • 3 standard reflections every 97 reflections intensity decay: none

Refinement

  • R[F 2 > 2σ(F 2)] = 0.034
  • wR(F 2) = 0.100
  • S = 0.95
  • 1405 reflections
  • 92 parameters
  • H-atom parameters constrained
  • Δρmax = 0.41 e Å−3
  • Δρmin = −0.38 e Å−3

Data collection: XSCANS (Bruker, 1996 [triangle]); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809034606/pv2198sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809034606/pv2198Isup2.hkl

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

Acknowledgments

The authors thank the National Science Foundation for grant No. ILI8951058.

supplementary crystallographic information

Comment

The synthesis of derivatives of 3-oxauracil has previously been reported (Warren et al., 1975) and an improved synthesis of the unsubstituted 3-oxauracil was reported by Rehberg & Glass (1995). The structure of the unsubstituted 3-oxauracil and its monohydrate have been reported (Copley et al., 2005). Three derivatives of 3-oxauracil (4-methyl, 4-bromo, and 4,5-dichloro) have been prepared in our laboratory in route to the synthesis of 1-aza-1,3-butadienes. In this paper, we report the crystal structure of the title compound, (I).

Unlike the hydrogen bonding observed in 4-methyl derivative (Parrish, Leuschner et al., 2009) resulting in staggered chains of molecules, in the crystal structure of of the title compound (Fig. 1), the molecules of (I) are held together by classical intermolecular hydrogen bonds of the type N—H···O resulting in dimeric units about inversion centers, forming eight membered ring systems which may be described in terms of graph set notation (Bernstein et al. 1994) as R22(8) ring motif (details have been given in Table 1 and Figure 2). The molecular dimensions in (I) agree well with the corresponding bond distances and angles reported for the above mentioned structures and 4-boromo derivative of 3-oxauracil (Parrish, Tivitmahaisoon et al., 2009).

Experimental

Dichloromaleic anhydride (3,4-dichlorofuran-2,5-dione) and trimethylsilyl azide were treated analogously to the syntheses reported for the 4-methyl (Parrish, Leuschner et al., 2009) and 4-bromo derivatives. Crystals of the title compound were grown from a solution of acetone at room temperature by slow evaporation.

Refinement

Hydrogen atom bonded to N3 was calculated and refined using a riding model using the N—H distance 0.88 Å with Uiso(H) = 1.2Ueq(N).

Figures

Fig. 1.
The molecular structure of the title compound, with atom labels and 50% probability displacement ellipsoids for non-H atoms.
Fig. 2.
The packing of the title compound viewed along the b axis and showing the H-bonded dimer formed by inversion related molecules.

Crystal data

C4HCl2NO3F(000) = 360
Mr = 181.96Dx = 1.980 Mg m3Dm = 1.92 Mg m3Dm measured by floatation
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 20 reflections
a = 10.2290 (16) Åθ = 10–12.5°
b = 5.2549 (8) ŵ = 1.00 mm1
c = 12.2766 (16) ÅT = 293 K
β = 112.359 (11)°Plates, colorless
V = 610.28 (16) Å30.38 × 0.33 × 0.15 mm
Z = 4

Data collection

Siemens R3m/V diffractometerRint = 0.053
Radiation source: fine-focus sealed tubeθmax = 27.6°, θmin = 2.2°
graphiteh = 0→13
θ–2θ scansk = 0→6
1566 measured reflectionsl = −15→14
1405 independent reflections3 standard reflections every 97 reflections
1235 reflections with I > 2σ(I) intensity decay: none

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.100w = 1/[σ2(Fo2) + (0.0666P)2 + 0.3617P] where P = (Fo2 + 2Fc2)/3
S = 0.95(Δ/σ)max < 0.001
1405 reflectionsΔρmax = 0.41 e Å3
92 parametersΔρmin = −0.38 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.042 (5)

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 (Å2)

xyzUiso*/Ueq
O10.89484 (14)0.7547 (3)0.20549 (12)0.0405 (4)
C20.9358 (2)0.6588 (4)0.12050 (17)0.0362 (4)
O21.03514 (16)0.7544 (3)0.10600 (14)0.0474 (4)
N30.86084 (17)0.4586 (3)0.05845 (14)0.0363 (4)
H30.88640.38920.00620.044*
C40.74604 (19)0.3625 (3)0.07572 (15)0.0325 (4)
Cl40.66660 (6)0.11274 (10)−0.01234 (4)0.0453 (2)
C50.7009 (2)0.4611 (4)0.15609 (16)0.0347 (4)
Cl50.55557 (6)0.35198 (11)0.17764 (5)0.0491 (2)
C60.7780 (2)0.6694 (4)0.22914 (17)0.0366 (4)
O60.75456 (18)0.7746 (3)0.30575 (15)0.0533 (4)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0479 (8)0.0401 (8)0.0369 (7)−0.0084 (6)0.0199 (6)−0.0094 (6)
C20.0401 (10)0.0363 (9)0.0321 (9)−0.0007 (8)0.0138 (8)0.0003 (7)
O20.0479 (8)0.0484 (9)0.0515 (9)−0.0126 (7)0.0251 (7)−0.0079 (7)
N30.0405 (8)0.0411 (9)0.0317 (8)−0.0050 (7)0.0188 (6)−0.0060 (7)
C40.0366 (9)0.0333 (9)0.0256 (8)−0.0020 (7)0.0097 (7)0.0002 (7)
Cl40.0530 (3)0.0453 (3)0.0375 (3)−0.0132 (2)0.0172 (2)−0.0125 (2)
C50.0387 (9)0.0387 (10)0.0286 (8)−0.0019 (8)0.0148 (7)0.0005 (7)
Cl50.0526 (3)0.0587 (4)0.0464 (3)−0.0136 (2)0.0303 (3)−0.0082 (2)
C60.0442 (10)0.0362 (9)0.0317 (9)−0.0008 (8)0.0171 (8)−0.0007 (7)
O60.0691 (10)0.0521 (9)0.0484 (9)−0.0073 (8)0.0334 (8)−0.0166 (7)

Geometric parameters (Å, °)

O1—C21.360 (2)C4—C51.342 (3)
O1—C61.406 (2)C4—Cl41.698 (2)
C2—O21.206 (2)C5—C61.444 (3)
C2—N31.353 (3)C5—Cl51.706 (2)
N3—C41.367 (2)C6—O61.192 (2)
N3—H30.8600
C2—O1—C6125.02 (15)C5—C4—Cl4123.46 (15)
O2—C2—N3124.69 (18)N3—C4—Cl4114.72 (14)
O2—C2—O1118.79 (18)C4—C5—C6119.33 (17)
N3—C2—O1116.51 (16)C4—C5—Cl5123.23 (15)
C2—N3—C4122.41 (16)C6—C5—Cl5117.44 (14)
C2—N3—H3118.8O6—C6—O1117.20 (18)
C4—N3—H3118.8O6—C6—C5127.99 (19)
C5—C4—N3121.82 (17)O1—C6—C5114.81 (16)
C6—O1—C2—O2177.41 (18)N3—C4—C5—Cl5178.26 (14)
C6—O1—C2—N3−3.1 (3)Cl4—C4—C5—Cl5−1.5 (3)
O2—C2—N3—C4−177.81 (19)C2—O1—C6—O6−179.15 (19)
O1—C2—N3—C42.7 (3)C2—O1—C6—C51.0 (3)
C2—N3—C4—C5−0.3 (3)C4—C5—C6—O6−178.2 (2)
C2—N3—C4—Cl4179.47 (15)Cl5—C5—C6—O61.5 (3)
N3—C4—C5—C6−2.0 (3)C4—C5—C6—O11.6 (3)
Cl4—C4—C5—C6178.29 (14)Cl5—C5—C6—O1−178.62 (13)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N3—H3···O2i0.861.992.845 (2)174

Symmetry codes: (i) −x+2, −y+1, −z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2198).

References

  • Bernstein, J., Etter, M. C. & Leiserowitz, L. (1994). Structure Correlation, edited by H.-B. Bürgi & J. D. Dunitz, Vol. 2, p. 431–507. New York: VCH.
  • Bruker (1996). XSCANS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Copley, R. C. B., Deprez, L. S., Lewis, T. C. & Price, S. L. (2005). CrystEngComm, 7, 421–428.
  • Parrish, D., Leuschner, F., Rehberg, G. M. & Kastner, M. E. (2009). Acta Cryst E65, o2354. [PMC free article] [PubMed]
  • Parrish, D., Tivitmahaisoon, P., Rehberg, G. M. & Kastner, M. E. (2009). Acta Cryst E65, o2355. [PMC free article] [PubMed]
  • Rehberg, G. M. & Glass, B. M. (1995). Org. Prep. Proced. Int 27, 651–652.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Warren, J. D., MacMillan, J. H. & Washburne, S. S. (1975). J. Org. Chem.40, 743–746.

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