5,7-Bis(benz­yloxy)-2-phenyl-4H-chromen-4-one

Angannan Nallasivam; Munirathinam Nethaji; Nagarajan Vembu; Buckle Jaswant; Nagarajan Sulochana

doi:10.1107/S160053680803938X

. 2008 Nov 29;64(Pt 12):o2490–o2491. doi: 10.1107/S160053680803938X

5,7-Bis(benzyloxy)-2-phenyl-4H-chromen-4-one

Angannan Nallasivam ^a, Munirathinam Nethaji ^b, Nagarajan Vembu ^c,^*, Buckle Jaswant ^d, Nagarajan Sulochana ^a

PMCID: PMC2959925 PMID: 21581453

Abstract

In the title compound, C₂₉H₂₂O₄, the chromene ring is almost planar with a small puckering [0.143 (2) Å]. The crystal structure is stabilized by C—H⋯O and C—H⋯π interactions. Edge-to-face (centroid–centroid distances of 3.894 and 3.673 Å) and face-to-face (centroid–centroid distance of 3.460 Å) π–π-ring electron interactions are also observed.

Related literature

For the biological and pharmacological properties of benzopyrans and their derivatives, see: Brooks (1998 ▶); Hatakeyama et al. (1988 ▶); Hyana & Saimoto (1987 ▶); Tang et al. (2007 ▶). For the importance of 4H-chromenes, see Liu et al. (2007 ▶); Wang, Fang et al. (2003 ▶); Wang, Zhang et al. (2003 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶); Desiraju (1989 ▶); Desiraju & Steiner (1999 ▶); Etter (1990 ▶).

Experimental

Crystal data

C₂₉H₂₂O₄
M _r = 434.47
Triclinic,
a = 9.496 (3) Å
b = 11.572 (3) Å
c = 11.767 (3) Å
α = 66.564 (4)°
β = 79.668 (5)°
γ = 73.836 (5)°
V = 1136.1 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (2) K
0.45 × 0.33 × 0.23 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1998 ▶) T _min = 0.963, T _max = 0.981
13435 measured reflections
5302 independent reflections
3534 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.059
wR(F ²) = 0.155
S = 1.05
5302 reflections
298 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680803938X/fb2125sup1.cif

e-64-o2490-sup1.cif^{(23.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680803938X/fb2125Isup2.hkl

e-64-o2490-Isup2.hkl^{(259.6KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C16—H16⋯O17ⁱ	0.93	2.57	3.212 (3)	127
C30—H30⋯Cg1ⁱⁱ	0.93	3.12	3.838	135
C8—H8⋯Cg2ⁱⁱⁱ	0.93	3.29	4.066	142
C27—H27B⋯Cg2ⁱⁱⁱ	0.97	3.18	4.083	156

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg1 and Cg2 are the centroids of the C20–C25 and C28–C33 rings, respectively.

Acknowledgments

AN thanks Dr Naresh Kumar and Dr G. Vengatachalam, School of Chemistry, Bharathidasan University, Tiruchirappalli, and Organica Aromatics Pvt Ltd Bangalore, India, for providing laboratory facilities.

supplementary crystallographic information

Comment

Chromenes (benzopyrans) and their derivatives have numerous biological and pharmacological properties (Tang et al., 2007) such as antisterility (Brooks, 1998) and anticancer activity (Hyana & Saimoto, 1987). In addition, polyfunctionalized chromene units are present in numerous natural products (Hatakeyama et al., 1988). 4H-chromenes are important synthons for some natural products (Liu et al., 2007). As a part of our structural investigations on 4H-chromene derivatives and compounds containing the benzopyran fragment, the single-crystal X-ray diffraction study on the title compound was carried out.

The chromene ring is almost planar similarly as those found in the related chromene derivatives (Wang, Zhang et al., 2003; Wang, Fang et al., 2003). The total puckering amplitude of the chromene ring is 0.143 (2) Å in the title structure. The interplanar angle between the chromene ring and the 2-phenyl ring is 6.8 (2)° thereby indicating the almost coplanar arrangement (Fig. 1). The benzyl group at C5 is slightly distorted from coplanarity with the chromene ring whereas the benzyl group at C7 is clearly non-coplanar as discerned from the respective interplanar angles of 7.6 (1)° and 70.01 (7)°.

The crystal structure is stabilized by the interplay of C–H···O and C–H···π interactions (Fig. 2, Table 1; Desiraju, 1989; Desiraju & Steiner, 1999). The C12–H12···O1 interaction is involved in a motif of a graph set S(5) (Bernstein et al., 1995; Etter, 1990). In another S(5) motif, C21–H21···O18 interaction is involved. The C8–H8···Cg2ⁱⁱ and C27–H27···Cg2ⁱⁱ (Cg2 is the centroid of the ring C28\C29···C33) interactions take part in the motif of the graph set R¹₂(7) where the entire Cg2 ring C28\C29···C33 is considered as a single acceptor atom.

There are two edge-to-face π···π interactions between Cg3 (O1\C2\C3\C4\C9\C10) and Cg4 (C5\C6\C7\C8\C9\C10) [2-x, 2-y, -z] at 3.894 Å with α = 4.44, β = 26.68, γ = 31.06° and perpendicular distances being 3.336 and 3.480 Å, Cg4 and Cg1 (C20\C21\C22\C23\C24\C25) [1-x, 2-y, -z] at 3.673 Å with α = 6.87, β = 20.69, γ = 16.31° and perpendicular distances being 3.525 and 3.436 Å. There is a face to face π···π interaction between two symmetery related Cg4 (2-x, 2-y, -z) rings at 3.460 Å with α = 0.00, β = 10.24, γ = 10.24° and perpendicular distances being 3.405 Å (α is the dihedral angle between the planes I and J where I is the plane of centroid 1 and J is the plane of centroid 2, β is the angle between the vector Cg(I)→Cg(J) and the normal to plane I, γ is the angle between the vector Cg(I)→ Cg(J) and the normal to plane J, the two perpendicular distances denote the perpendicular distances of Cg(I) on ring J and Cg(J) on ring I).

Experimental

A suspension of chrysin (3.93 mmol, 1.00 g) and potassium carbonate (11.81 mmol, 1.64 g) in dimethyl formamide (10 ml) were added into a round bottom flask. The reaction mixture was heated to 383 K for 2–3 h. The reaction mixture was then cooled to 353 K and benzyl chloride (15.74 mmol, 1.99 g) was slowly added to the reaction mixture with the help of a dropping funnel. The reaction mixture was maintained for 8–9 h at 353 K and monitored by a high pressure liquid chromatography (HPLC). After completion of the reaction, the content was quenched with water and stirred for 30–45 min at 303 K. The obtained crude solid was filtered and washed with plenty of water followed by methanol and dried under vacuum at 343 K. The crude product was dissolved in 20 ml of 1:1 (volume) mixture of dichloromethane and n-hexane. The clear solution was kept for a week without stirring. Diffraction quality prism shaped crystals of average size 0.3 mm were obtained which were filtered and washed with n-hexane and dried under vacuum at 343 K. Yield: 90%