3-Benzyl­idene-6-methoxy­chroman-4-one

T Augustine; Scholastica Mary Vithiya; V Ramkumar; Charles C Kanakam

doi:10.1107/S1600536808031541

. 2008 Oct 9;64(Pt 11):o2080. doi: 10.1107/S1600536808031541

3-Benzylidene-6-methoxychroman-4-one

T Augustine ^a,^*, Scholastica Mary Vithiya ^b, V Ramkumar ^c, Charles C Kanakam ^d

PMCID: PMC2959532 PMID: 21580945

Abstract

In the title compound, C₁₇H₁₄O₃, the dihedral angle between the phenyl ring and the benzene ring of the chromanone moiety is 67.78 (3)°. The six-membered heterocyclic ring of the chromanone moiety adopts a half-chair conformation. The structure is stabilized by weak intermolecular C—H⋯O interactions that link the molecules into inversion dimers.

Related literature

For background literature, see: Finch & Tamm (1970 ▶); Geen et al.(1996 ▶); Tietze & Gerlitzer (1997 ▶); Cremer & Pople (1975 ▶). For a related structure, see: Suresh et al. (2007 ▶).

Experimental

Crystal data

C₁₇H₁₄O₃
M _r = 266.28
Triclinic,
a = 7.2678 (2) Å
b = 8.3151 (2) Å
c = 11.7999 (4) Å
α = 95.964 (1)°
β = 103.828 (1)°
γ = 104.042 (1)°
V = 661.74 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 (2) K
0.45 × 0.42 × 0.38 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ▶) T _min = 0.960, T _max = 0.966
8868 measured reflections
3041 independent reflections
2404 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.116
S = 1.04
3041 reflections
186 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 (Bruker, 2004 ▶); data reduction: SAINT-Plus (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808031541/fl2222sup1.cif

e-64-o2080-sup1.cif^{(18KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808031541/fl2222Isup2.hkl

e-64-o2080-Isup2.hkl^{(149.2KB, 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
C6—H6⋯O1ⁱ	0.93	2.53	3.4293 (18)	163

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The chroman-4-one (2,3-dihydro-4-oxo-4H-1-benzopyran) ring system occupies an important position among oxygen heterocyclics and features in a wide variety of compounds of biological and medicinal interest (Finch & Tamm, 1970). Many biologically active natural products containing a chroman ring system have been synthesized via 2-substituted chroman-4-one intermediates including alpha-tocopherol (vitamin E) (Geen et al., 1996). 3-arylidene-4-chromanones have also been isolated as natural products belonging to the class of compounds called homoisoflavonoids(Tietze & Gerlitzer, 1997).

The geometric parameters in the title compound agree with values reported for a similar structure (Suresh et al., 2007). The dihedral angle between the benzene ring of the chromanone moiety and the phenyl ring is 67.78 (3)°. The Chromanone moiety is fused with a six membered heterocyclic ring and the study of torsion angles, asymmetry parameters and least-square plane calculations shows that the chromanone adopts a half chair conformation with a deviation of C14 from the C8/C9/C15/C16/O2 plane by 0.616 (4) Å, Q₂= 0.4053 (14) Å, Q₃= -0.2052 (13)Å, and Q_T=0.4543 (14)Å (Cremer &Pople, (1975). The structure is stabilized by weak intermolecular C—H···O interaction that link the molecules into pairs around a center (Table 1). No other short intermolecular interactions were found.

Experimental

Methyl-(2Z)-2-bromo methyl-3-aryl prop-2-enoate (0.006 mole, 1.53 g) was treated with 4-methoxy phenol (0.006 mole, 0.9 ml) in the presence of potassium carbonate in acetone at reflux temperature for 3 hrs. The pure ester, 3-aryl-2-(4-methoxy)-phenoxymethylprop-2-enoate was obtained after purifying it using silica gel and column chromatography (3% ethyl acetate - hexane). Hydrolysis of this ester was carried out with KOH in aqueous 1,4–dioxane at room temperature. The reaction mixture was acidified and the precipitated acid was purified by recrystalization. Finally the acid was treated with triflouroacetic anhydride and the reaction mixture was refluxed in dichloro- methane for 1 hr. It was further purified by column chromatography (silica gel-3% ethyl acetate - hexane) and the crystals used for data collection were obtained by slow evaporation from methanol.