Crystal structure of 6,7-di­chloro-4-oxo-4H-chromene-3-carbaldehyde

Yoshinobu Ishikawa

doi:10.1107/S2056989015014644

. 2015 Aug 12;71(Pt 9):o652–o653. doi: 10.1107/S2056989015014644

Crystal structure of 6,7-dichloro-4-oxo-4H-chromene-3-carbaldehyde

Yoshinobu Ishikawa ^a,^*

PMCID: PMC4555387 PMID: 26396886

Abstract

In the title compound, C₁₀H₄Cl₂O₃, a dichlorinated 3-formylchromone, the non-H atoms of the 4H-chromene ring are essentially coplanar (r.m.s. = 0.0188 Å), with the largest deviation from the least-squares plane [0.043 (2) Å] being for the pyran C=O C atom. The α,β-unsaturated carbonyl O atom deviates from the least-square plane by 0.124 (2) Å. The dihedral angle between the chromone and formyl least-square planes is 6.76 (3)°. In the crystal, molecules are linked through C—H⋯O hydrogen bonds between the translation-symmetry and inversion-symmetry equivalents to form tetrads, which are further assembled by stacking interactions [centroid–centroid distance between the benzene rings = 3.769 (2) Å]. van der Waals contacts are found between the Cl atoms at the 6-position and the Cl atoms at 7-position of the glide-reflection-symmetry equivalents [Cl⋯Cl = 3.4785 (16) Å, C—Cl⋯Cl = 160.23 (7)° and Cl⋯Cl—C = 122.59 (7)°].

Keywords: crystal structure, chromone, hydrogen bonding, halogen–halogen contact, stacking interaction

Related literature

For related structures, see: Ishikawa & Motohashi (2013 ▸); Ishikawa (2014a ▸,b ▸, 2015 ▸). For halogen bonding and halogen⋯halogen interactions, see: Auffinger et al. (2004 ▸); Metrangolo et al. (2005 ▸); Metrangolo & Resnati (2014 ▸); Mukherjee & Desiraju (2014 ▸); Wilcken et al. (2013 ▸); Sirimulla et al. (2013 ▸); Persch et al. (2015 ▸). graphic file with name e-71-0o652-scheme1.jpg

Experimental

Crystal data

C₁₀H₄Cl₂O₃
M _r = 243.05
Monoclinic,
a = 3.7695 (13) Å
b = 6.1465 (16) Å
c = 39.431 (13) Å
β = 90.72 (3)°
V = 913.5 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.69 mm⁻¹
T = 140 K
0.30 × 0.25 × 0.10 mm

Data collection

Rigaku AFC–7R diffractometer
Absorption correction: ψ scan (North et al., 1968 ▸) T _min = 0.574, T _max = 0.934
5075 measured reflections
2089 independent reflections
1747 reflections with F ² > 2.0σ(F ²)
R _int = 0.052
3 standard reflections every 150 reflections intensity decay: 0.6%

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.098
S = 1.04
2089 reflections
136 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: WinAFC Diffractometer Control Software (Rigaku, 1999 ▸); cell refinement: WinAFC Diffractometer Control Software; data reduction: WinAFC Diffractometer Control Software; program(s) used to solve structure: SIR2011 (Burla et al., 2012 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015 ▸); molecular graphics: CrystalStructure (Rigaku, 2015 ▸); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015014644/zl2636sup1.cif

e-71-0o652-sup1.cif^{(174.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015014644/zl2636Isup2.hkl

e-71-0o652-Isup2.hkl^{(167.8KB, hkl)}

Click here for additional data file.^{(3.4KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015014644/zl2636Isup3.cml

Click here for additional data file.^{(3.2MB, tif)}

a H a b H b c d H e . DOI: 10.1107/S2056989015014644/zl2636fig1.tif

Sphere models of the crystal structures of (a) 6-chloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2014a), (b) 7-chloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2014b), (c) 6,8-dichloro-4-oxochromene-3-carbaldehyde (Ishikawa & Motohashi, 2013), (d) 7,8-dichloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2015) and (e) the title compound (this work).

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015014644/zl2636fig2.tif

The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. Hydrogen atoms are shown as small spheres of arbitrary radius.

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015014644/zl2636fig3.tif

A packing view of the title compound. C–H⋯O hydrogen bonds are represented by dashed lines.

CCDC reference: 1416757

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C1H1O3ⁱ	0.95	2.34	3.187(3)	148(1)
C7H3O2ⁱⁱ	0.95	2.26	3.129(2)	151(1)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The University of Shizuoka is acknowledged for instrumentational support.

supplementary crystallographic information

S1. Comment

Halogen bonding is an electrostatic interaction between an electrophilic region of a halogen atom and a nucleophilic region of an atom, and has attracted much attention in medicinal chemistry, chemical biology, supramolecular chemistry and crystal engineering (Auffinger et al., 2004, Metrangolo et al., 2005, Wilcken et al., 2013, Sirimulla et al., 2013, Mukherjee & Desiraju, 2014, Metrangolo & Resnati, 2014, Persch et al., 2015). This is characterized by a short contact between the two atoms.

I have reported the crystal structures of chlorinated 3-formylchromones 6-chloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2014a), 7-chloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2014b), 6,8-dichloro-4-oxochromene-3-carbaldehyde (Ishikawa & Motohashi, 2013) and 7,8-dichloro-4-oxo-4H-chromene-3-carbaldehyde (Ishikawa, 2015). As for the monochlorinated 3-formylchromones, van der Waals contacts are observed between the formyl oxygen atom and the chlorine atom at 6-position in 6-chloro-4-oxo-4H-chromene-3-carbaldehyde (Fig. 1a), and between the chlorine atoms at 7-position in 7-chloro-4-oxo-4H-chromene-3-carbaldehyde (Fig. 1b). On the other hand, as for the dichlorinated 3-formylchromones, halogen bonds are observed between the formyl oxygen atom and the chlorine atom at 8-position in 6,8-dichloro-4-oxochromene-3-carbaldehyde (Fig. 1c), and between the formyl oxygen atom and the chlorine atom at 7-position in 7,8-dichloro-4-oxo-4H-chromene-3-carbaldehyde (Fig. 1d). As part of my investigation into these types of chemical bonding, I herein report the crystal structure of a dichlorinated 3-formylchromone 6,7-dichloro-4-oxo-4H-chromene-3-carbaldehyde. The main objective of this study is to reveal the interaction modes of the chlorine substituents of the title compound in the solid state.

The mean deviation of the least-square plane for the non-hydrogen atoms of the 4H-chromene ring is 0.0188 Å, and the largest deviation is 0.043 (2) Å for the C3 atom (Fig. 2). The α,β-unsaturated carbonyl O2 atom deviates from the least-square plane by 0.124 (2) Å. The dihedral angle between the chromene least-square plane and the formyl C2–C10–O3 plane is 6.76 (3)°.

In the crystal, the molecules are linked through C–H···O hydrogen bonds between the translation-symmetryⁱ and inversion-symmetry equivalents^ii,iii to form tetrads [i: x – 1, y + 1, z, ii: –x + 1, –y, –z + 1, iii: –x + 2, –y + 1, –z + 1], which are further assembled by stacking interactions [centroid–centroid distance between the benzene rings of the 4H-chromene units = 3.769 (2) Å], as shown in Fig. 3.

Van der Waals contacts are found between the chlorine atoms at 6-position and the chlorine atoms at 7-position of the glide-reflection-symmetry equivalents^iv [Cl1···Cl2^iv = 3.4785 (16) Å, C5–Cl1···Cl2^iv = 160.23 (7)°, Cl1···Cl2^iv–C6^iv = 122.59 (7)°, iv: –x + 1, y – 1/2, –z + 1/2], as shown in Fig. 1e. Thus, short contacts are observed for the chlorine atoms in the title compound. The interaction modes of the chlorine atoms in these dichlorinated 3-formylchromones might depend on how strongly the chlorine atoms interact with the oxygen and other vicinal chlorine atoms intramolecularly. These findings could be helpful to rational drug design considering halogen bonding.

S2. Experimental

To a solution of 4',5'-dichloro-2'-hydroxyacetophenone (4.8 mmol) in N,N-dimethylformamide (15 ml) was added dropwise POCl₃ (12.0 mmol) at 0 °C. After the mixture was stirred for 14 h at room temperature, water (50 ml) was added. The precipitates were collected, washed with water and dried in vacuo (yield: 65%). ¹H NMR (400 MHz, CDCl₃): δ = 7.71 (s, 1H), 8.37 (s, 1H), 8.52 (s, 1H), 10.35 (s, 1H). Single crystals suitable for X-ray diffraction were obtained from a 1,2-dichloroethane solution of the title compound at room temperature.