5,7-Dimeth­oxy-2-phenyl-4H-chromen-4-one

Angannan Nallasivam; Munirathinam Nethaji; Nagarajan Vembu; Venkatraman Ragunathan; Nagarajan Sulochana

doi:10.1107/S1600536809003948

. 2009 Feb 11;65(Pt 3):o504–o505. doi: 10.1107/S1600536809003948

5,7-Dimethoxy-2-phenyl-4H-chromen-4-one

Angannan Nallasivam ^a, Munirathinam Nethaji ^b, Nagarajan Vembu ^c,^*, Venkatraman Ragunathan ^d, Nagarajan Sulochana ^a

PMCID: PMC2968465 PMID: 21582168

Abstract

The asymmetric unit of the title compound, C₁₇H₁₄O₄, contains two independent molecules which differ in the relative orientations of the phenyl rings with repect to the essentially planar [maximum deviations of 0.029 (2) and 0.050 (2) Å in the two molecules] chromene fused-ring system, forming dihedral angles of 10.3 (5) and 30.86 (5)° in the two molecules. The crystal structure is stabilized by weak C—H⋯O and C—-H⋯π interactions, and π–π stacking interactions.

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 bonding, see: Bernstein et al. (1995 ▶); Desiraju (1989 ▶); Desiraju & Steiner (1999 ▶); Etter (1990 ▶).

Experimental

Crystal data

C₁₇H₁₄O₄
M _r = 282.28
Triclinic,
a = 7.3938 (17) Å
b = 11.430 (3) Å
c = 16.547 (4) Å
α = 92.414 (4)°
β = 102.723 (4)°
γ = 91.916 (4)°
V = 1361.5 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 (2) K
0.35 × 0.32 × 0.29 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.967, T _max = 0.977
15401 measured reflections
6096 independent reflections
3897 reflections with I > 2σ(I)
R _int = 0.042

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.126
S = 1.01
6096 reflections
386 parameters
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.17 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/S1600536809003948/lh2766sup1.cif

e-65-0o504-sup1.cif^{(27.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809003948/lh2766Isup2.hkl

e-65-0o504-Isup2.hkl^{(298.4KB, 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
C17A—H17A⋯O1A	0.93	2.38	2.713 (2)	101
C13B—H13E⋯O11Aⁱ	0.96	2.37	3.169 (2)	141
C19A—H19A⋯O11Bⁱⁱ	0.93	2.57	3.256 (2)	131
C19A—H19A⋯O12Bⁱⁱ	0.93	2.55	3.442 (2)	161
C15B—H15D⋯Cg5	0.96	2.85	3.786	166

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Symmetry codes: (i) Inline graphic ; (ii) . Cg5 is the centroids of the C16A–C21A ring.

Table 2. π–π Stacking interactions (Å, °).

Cg_i	Cg_j	Cg_i⋯Cg_j	α	perp
Cg1	Cg2	3.972 (1)	10.9	3.575
Cg1	Cg4	3.646 (1)	8.1	3.578
Cg1	Cg4ⁱ	3.785 (1)	8.1	3.535
Cg2	Cg3ⁱ	3.792 (1)	9.9	3.599
Cg2	Cg3	3.883 (1)	9.9	3.743
Cg3	Cg4ⁱ	3.769 (1)	7.1	3.516

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Symmetry code: (i) Inline graphic . Cg1, Cg2, Cg3, and Cg4 are the centroids of the O1A/C2A–C4A/C9A/C10A, O1B/C2B–C4B/C9B/C10B, C5A–C10A and C5B–C10B rings, respectively. α is the dihedral angle between ring planes and perp is the perpendicular distance between ring planes.

Acknowledgments

AN thanks Dr S. Kannan and Dr B. S. Krishnamurthy, 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 two molecules (A and B) in the asymmetric unit are shown in Fig. 1. In each molecule, the chromene ring is essentially planar as found in the related chromene derivatives (Wang, Zhang et al., 2003; Wang, Fang et al., 2003). In the title compound, the maximun deviation for the chromene ring in each molecule is 0.029 (2) and 0.050 (2) Å, for atoms C4A and C4B, respectively. The dihedral angle between the chromene ring mean-plane and the phenyl ring is 10.3 (5)° in molecule A and 30.86 (5)° in molecule B. The methoxy substituent at C5 forms dihedral angles of 8.4 (1) and 2.1 (1)° in molecules A and B, respectively. The methoxy substituent at C7 forms dihedral angles of 1.75 (1) & 12.09 (8)° in molecules A and B, respectively.

In the crystal structure (see Fig.2), the intramolecular C17A–H17A···O1A interaction generates a S(5) ring motif (Bernstein et al., 1995; Etter, 1990) and the C19A–H19A···O11Bⁱⁱ and C19A—H19A···O12Bⁱⁱ interactions constitute two bifurcated weak hydrogen bonds bonds that generate a R²₁(6) ring motif. In addition, the crystal structure contains significant C—H···π interactions (Table 1) and π..π interactions (Table 2) whose distances agree with those described by Desiraju & Steiner (1999) and Desiraju (1989).

Experimental

In to the RBF, a suspension of chrysin (1 g, 3.93 mmol) and potassium carbonate (1.62 g, 11.81 mmol) in dimethyl formamide (10 ml) were added. The reaction mixture was heated to 383 K for 2–3 hrs. The reaction mixture was cooled to 313 K and methyl iodide (10 ml, 15.74 mmol) was slowly added with the help of dropping funnel. The reaction mixture was maintained for 8–9 hr at 313 K and monitored by HPLC. After completion of the reaction, the contents were quenched with water and stirred for 30–45 min at 303 K. The crude solid obtained was filtered and washed with plenty of water followed by methanol and dried under vacuum at 343 K. The compound was purified by column chromatography using ethyl acetate: n-hexane (30:70) as diluent. All the fractions were analyzed by HPLC. The highly pure column fractions were mixed and concentrated in a rotary evaporator. The resulting product was recrystallized from dichloromethane: n-hexane mixture (10 ml each). The obtained crystals were washed with n-hexane and dried under vacuum at 348 K. Yield: 70%