3-(3,4-Dimeth­oxy­benz­yl)chroman-4-one

S Shalini; C R Girija; Lalitha Simon; K K Srinivasan; T V Venkatesha; M M Jotani

doi:10.1107/S1600536813000925

. 2013 Jan 16;69(Pt 2):o241. doi: 10.1107/S1600536813000925

3-(3,4-Dimethoxybenzyl)chroman-4-one

S Shalini ^a, C R Girija ^a,^*, Lalitha Simon ^c, K K Srinivasan ^c, T V Venkatesha ^d, M M Jotani ^e

PMCID: PMC3569774 PMID: 23424520

Abstract

In the title compound, C₁₈H₁₈O₄, the six-membered chroman-4-one ring adopts an envelope conformation with the C atom bonded to the bridging CH₂ atom as the flap. The dihedral angle between the mean plane of the fused pyranone ring and the dimethoxy-substituted benzene ring is 89.72 (2)°. In the crystal, adjacent molecules are linked via C—H⋯π interactions.

Related literature

For the biological activity and pharmaceutical properties of chromenes(benzopyrans) and a similar structure, see: Jasinski et al. (2010 ▶). For bond-length data see: Allen et al. (1987 ▶). For ring conformations, see: Cremer & Pople (1975 ▶)

Experimental

Crystal data

C₁₈H₁₈O₄
M _r = 298.33
Monoclinic,
a = 30.414 (4) Å
b = 5.453 (3) Å
c = 20.661 (5) Å
β = 118.568 (3)°
V = 3009.4 (19) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 295 K
0.30 × 0.20 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.954, T _max = 0.991
13379 measured reflections
2802 independent reflections
1955 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.142
S = 1.03
2802 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012 ▶) and CAMERON (Watkin et al., 1993 ▶); software used to prepare material for publication: PARST (Nardelli, 1995 ▶) and WinGX (Farrugia, 2012 ▶).

Supplementary Material

Click here for additional data file.^{(18.9KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813000925/hg5275sup1.cif

e-69-0o241-sup1.cif^{(18.9KB, cif)}

Click here for additional data file.^{(134.8KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813000925/hg5275Isup2.hkl

e-69-0o241-Isup2.hkl^{(134.8KB, hkl)}

Click here for additional data file.^{(6KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813000925/hg5275Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg is the centroid of the C11–C16 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C18—H18A⋯Cg ⁱ	0.96	2.87	3.755 (4)	154

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Dr Babu Varghese, Scientific Officer, Sophisticated Analytical Instrument Facility (SAIF), Indian Institute of Technology (IIT), Chennai, India, for the data collection. SS and CRG also thank the Rashtriya Sikshana Samithi Trust (RSST) and the Principal, Sri Shivananda Memorial Rashtriya Vidyalaya (SSMRV) Degree College, Bangalore, for their constant support and encouragement in carrying out this work.

supplementary crystallographic information

Comment

Homoisoflavonones have wide spectrum of biological activity. In the past decades they are widely used as antifungal, antiviral, antimutagenic,antiproliferative, antioxidant, and protein tyrosine kinase (PTK) inhibitor activities (Jasinski et al., 2010). Because of their wide range of pharmacological activity, the title compound (I) was synthesized and the crystal structure determined.

The bond distances and angles are found to have normal values (Allen et al., 1987). The pyranone ring has adopted the envelope conformation (Cremer & Pople, 1975) as shown in Fig.1. The ring puckering parameters q₂ = 0.3696 (2) Å,q₃=0.2785 (3) Å, Q_T = 0.4628 Å, and φ = 276.96 (2)°, are indicative of an envelope conformation. The carbonyl ketone, being an electron-withdrawing group, makes the internal aromatic angle 118.17 (3)° at the C9 atom. The electronegative oxygen of the fused pyranone ring shows no change in the internal aromatic angle at the C5 atom. The six membered fused pyranone ring makes a dihedral angle of 89.72 (2)° with the dimethoxy substituted phenyl ring.

No classical inter- or intra-molecular hydrogen bonds are observed. The packing of the title compound is stabilized into a three-dimensional network by C—H···π intermolecular interactions, which serve to link inversion-related sheets (Fig 2).

Experimental

2'-Hydroxydihydrochalcone (0.1 g) was dissolved in ethanol (10 ml) and refluxed with paraformaldehyde (0.022 g) and 50% aqueous diethylamine (0.2 ml) for 7 hrs. Ethanol was distilled off and the residue was taken up in ethyl acetate. The ethyl acetate layer washed with water then with dilute HCl and finally with water. Ethyl acetate was distilled off and the oily residue was column chromatographed over silica using pet ether(7): ethyl acetate(3) as eluent to get the 3-(3,4-dimethoxybenzyl)-2,3-dihydro-4H-chroman-4-one. Single crystals of the title compound were grown using methanol as solvent by slow evaporation technique and white needle-like crystals were harvested at room temperature. M.P. 397 K. Yield: 65%. IR(KBr):3001,2947,1689 cm^-1. ¹H-NMR,(400 MHz, DMSO) 4.3(dd,J=11.2,4.4Hz,1H,2-H), 4.2(dd,J=11.6, 9.2Hz,1H,2-H), 2.6(m,1H,3-H), 3.1(m,2H,9 -H), 3.7[S,6H,3 ,4 (2x OCH3)], 7.7(dd,J=8.1, 0.6Hz,1H, Ar-H), 7.5(m, 1H,Ar-H), 6.7(dd,J=8.4 ,2Hz,1H,Ar-H).