Crystal structure of 3-[2-(4-methyl­phen­yl)ethyn­yl]-2H-chromen-2-one

Ignez Caracelli; Stella H Maganhi; Hélio A Stefani; Karina Gueogjian; Edward R T Tiekink

doi:10.1107/S2056989014027790

. 2015 Jan 10;71(Pt 2):o90–o91. doi: 10.1107/S2056989014027790

Crystal structure of 3-[2-(4-methylphenyl)ethynyl]-2H-chromen-2-one

Ignez Caracelli ^a,^*, Stella H Maganhi ^a, Hélio A Stefani ^b, Karina Gueogjian ^b, Edward R T Tiekink ^c

PMCID: PMC4384545 PMID: 25878887

Abstract

The coumarin ring system in the title asymmetric alkyne, C₁₈H₁₂O₂, is approximately planar (r.m.s. deviation of the 11 non-H atoms = 0.048 Å), and is inclined with respect to the methylbenzene ring, forming a dihedral angle of 33.68 (4)°. In the crystal, supramolecular zigzag chains along the c-axis direction are formed via weak C—H⋯O hydrogen bonds, and these are connected into double layers via weak C—H⋯π interactions; these stack along the a axis.

Keywords: crystal structure, coumarins, asymmetric alkyne, hydrogen bonding, C—H⋯π interactions

Related literature

For the biological activity of coumarins, see: Wu et al. (2009 ▸). For background to previous work on coumarins, see: Stefani et al. (2012 ▸). For a related structure, see: Elangovan et al. (2004 ▸). For synthetic details, see: Gueogjian (2011 ▸). graphic file with name e-71-00o90-scheme1.jpg

Experimental

Crystal data

C₁₈H₁₂O₂
M _r = 260.28
Monoclinic,
a = 8.4695 (2) Å
b = 10.6759 (2) Å
c = 14.5208 (2) Å
β = 98.093 (2)°
V = 1299.89 (4) Å³
Z = 4
Cu Kα radiation
μ = 0.69 mm⁻¹
T = 100 K
0.30 × 0.25 × 0.20 mm

Data collection

Agilent CCD diffratcometer diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▸) T _min = 0.834, T _max = 1.000
5023 measured reflections
2664 independent reflections
2416 reflections with I > 2σ(I)
R _int = 0.015

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.105
S = 1.04
2664 reflections
182 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▸); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2014 (Burla et al., 2015 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸) and DIAMOND (Brandenburg, 2006 ▸); software used to prepare material for publication: MarvinSketch (ChemAxon, 2010 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989014027790/hg5424sup1.cif

e-71-00o90-sup1.cif^{(189.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989014027790/hg5424Isup2.hkl

e-71-00o90-Isup2.hkl^{(146.4KB, hkl)}

Click here for additional data file.^{(5.1KB, cml)}

Supporting information file. DOI: 10.1107/S2056989014027790/hg5424Isup3.cml

Click here for additional data file.^{(1MB, tif)}

. DOI: 10.1107/S2056989014027790/hg5424fig1.tif

The molecular structure of the title compound showing the atom-labelling scheme and displacement ellipsoids at the 70% probability level.

Click here for additional data file.^{(1,006.9KB, tif)}

c . DOI: 10.1107/S2056989014027790/hg5424fig2.tif

A view of the zigzag supramolecular sustained by weak C—H⋯O hydrogen bonds (orange dashed lines) and aligned along the c axis in the crystal packing.

Click here for additional data file.^{(2.4MB, tif)}

c . DOI: 10.1107/S2056989014027790/hg5424fig3.tif

A view in projection down the c axis of the unit-cell contents. The weak C—H⋯O and C—H⋯π interactions are shown as orange and purple dashed lines, respectively.

CCDC reference: 1040558

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

Table 1. Hydrogen-bond geometry (, ).

Cg1 and Cg2 are the centroids of the C4C9 and C12C17 rings, respectively.

DHA	DH	HA	D A	DHA
C7H7O2ⁱ	0.95	2.48	3.1425(14)	127
C13H13Cg1ⁱⁱ	0.95	2.94	3.4416(12)	115
C5H5Cg2ⁱⁱⁱ	0.95	3.00	3.7780(13)	140

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

Acknowledgments

The Brazilian agencies CNPq (306121/2013–2 to IC and 308320/2010–7 to HAS), FAPESP and CAPES are acknowledged for financial support.

supplementary crystallographic information

S1. Introduction

Coumarins are heterocycles presenting a wide range of different biological activities (Wu et al., 2009). As part of our on-going interest in the synthesis of coumarin derivatives with biological activity (Stefani et al., 2012) the title compound was synthesized.

S2. Experimental

S2.1. Synthesis and crystallization

The title compound was prepared as per Gueogjian (2011). 3-Bromo coumarin (112.5 mg, 0.5 mmol), potassium trifluoroborate salt (0.55 mmol), PdCl₂(dppf).CH₂Cl₂ (41 mg, 10 mol%), i-Pr₂NEt (0.3 mL, 1.5 mmol)and 1,4-dioxane/H₂O (2/1, 3 mL), in acetonitrile (20 mL) were added to a two-necked round-bottomed flask equipped with a reflux condenser under N₂. The reaction mixture was heated under reflux at 353 K, and was monitored by TLC and GC analysis. After the consumption of the 3-bromocoumarin, the mixture was extracted twice with ethyl acetate (50 mL). The organic phase was separated, dried over MgSO₄ and concentrated under vacuum. The residue was purified by flash chromatography (ethyl acetate/hexane 10:90). The title compound was obtained as a brown solid in 70% yield. Suitable crystals were obtained by slow evaporation from ethyl acetate/hexane.

S2.2. Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H = 0.95 to 0.98 Å) and were included in the refinement in the riding model approximation, with U_iso(H) = 1.2–1.5U_eq(C).

S3. Results and discussion

The title compound, Fig. 1, is an asymmetric alkyne. The coumarin residue is approximately planar with the r.m.s. deviation of the 11 non-hydrogen atoms being 0.048 Å; the maximum deviations from their least-squares plane are 0.078 (1) and -0.066 (1) Å for the C2 and O2 atoms, respectively. Overall, the molecule is non-planar as seen in the dihedral between the fused ring system and the methylbenzene ring of 33.68 (4)°.

The most closely related structure in the literature is of the derivative where the methyl group of the title compound has been replaced by an isopropoxy group (Elangovan et al., 2004). In this case, with the exception of the terminal methyl groups, the molecule is planar with the dihedral angle between the 11 non-hydrogen atoms of the courmarin residue the benzene ring being 0.88 (6)°.

Weak coumarin-C₆—C—H···O(exocyclic) hydrogen bonding gives rise to a supramolecular chain aligned along the c axis, Table 1 and Fig. 2. The chains are connected into double layers, sustained by weak C—H···π interactions, that stack along the a axis with no specific interactions between them, Table 2 and Fig. 3.