Ethyl 4-(2-fur­yl)-2-oxochroman-3-carboxyl­ate

Maddela Prabhakar; J S N Reddy; N Ravi Kumar; S Viswanadha Ganesh; K Anand Solomon

doi:10.1107/S1600536810016193

. 2010 May 12;66(Pt 6):o1310. doi: 10.1107/S1600536810016193

Ethyl 4-(2-furyl)-2-oxochroman-3-carboxylate

Maddela Prabhakar ^a, J S N Reddy ^a, N Ravi Kumar ^a, S Viswanadha Ganesh ^a, K Anand Solomon ^a,^*

PMCID: PMC2979556 PMID: 21579405

Abstract

The title compound, C₁₆H₁₄O₅, was prepared from the reaction of 3-carbethoxycoumarin with furan in the presence of AlCl₃ as catalyst. In the crystal, intermolecular C—H⋯O hydrogen-bonding interactions between four molecules lead to a tetramer in the unit cell. The furan ring is antiperiplanar [C—C—C—O = 167.9 (13)°] and the ethoxycarbonyl group is (−)anticlinal [C—C—C—O = −128.6 (14)°] to the lactone ring.

Related literature

For the medicinal and biological activity of coumarins and their derivatives, see: Borges et al. (2005 ▶); Kontogiorgis & Hadjipavlou-Litina (2005 ▶); Gursoy & Karali (2003 ▶); Prabhakar et al. (2010 ▶). For the assignment of conformations and the orientation of the substituents, see: Nardelli (1983 ▶, 1995 ▶); Klyne & Prelog (1960 ▶). graphic file with name e-66-o1310-scheme1.jpg

Experimental

Crystal data

C₁₆H₁₄O₅
M _r = 286.27
Monoclinic,
a = 10.393 (3) Å
b = 8.459 (3) Å
c = 15.819 (5) Å
β = 95.464 (5)°
V = 1384.5 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.34 × 0.24 × 0.20 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T _min = 0.966, T _max = 0.980
13767 measured reflections
2711 independent reflections
2099 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.111
S = 1.04
2711 reflections
227 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.16 e Å⁻³

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

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810016193/ds2028sup1.cif

e-66-o1310-sup1.cif^{(15.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810016193/ds2028Isup2.hkl

e-66-o1310-Isup2.hkl^{(133.1KB, 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
C3—H3⋯O3ⁱ	0.972 (15)	2.696 (15)	3.576 (2)	150.8 (11)
C16—H16B⋯O2ⁱⁱ	0.96	2.70	3.549 (3)	148
C16—H16A⋯O2ⁱⁱⁱ	0.96	2.96	3.841 (3)	153
C8—H8⋯O3^iv	0.96 (2)	2.94 (2)	3.611 (3)	128.2 (15)
C11—H11⋯O4^v	0.93 (2)	2.73 (2)	3.501 (3)	140.9 (17)
C13—H13⋯O2^vi	1.01 (2)	2.54 (2)	3.456 (3)	151.0 (17)
C12—H12⋯O4^vii	0.95 (2)	2.74 (2)	3.478 (3)	134.9 (16)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

We thank the Director, Institute of Life Sciences, for support and also the Dean, School of Chemistry, University of Hyderabad, for the X-ray crystallographic data.

supplementary crystallographic information

Comment

We have synthesized and reported our serendipitous observations on the Diels-Alder reaction of 3-carbethoxy coumarin with furan, followed by a ring opening to yield Michael product, 3-carbethoxy-4-(2-furyl)-chroman-2-one in good yields.

Experimental

3-Carbethoxy coumarin (3 m mol) was taken into 30 mmol of furan and 10 mol% of AlCl₃ catalyst was added. The reaction mixture was stirred at room temperature for 24 hours. After completion of the reaction, the excess of the furan was distilled off and extracted thrice with water/dichloromethane. The product was separated from flash column chromatography and recrystallized from dichloromethane.