3-[(E)-1-(Benzyl­oxyimino)eth­yl]-2-oxo-2H-chromen-7-yl acetate

Hui Wang; Su-hua Xu; Zhuo Zeng; Yong-hong Zhang

doi:10.1107/S1600536810003454

. 2010 Feb 3;66(Pt 3):o511. doi: 10.1107/S1600536810003454

3-[(E)-1-(Benzyloxyimino)ethyl]-2-oxo-2H-chromen-7-yl acetate

Hui Wang ^a,^*, Su-hua Xu ^a, Zhuo Zeng ^a, Yong-hong Zhang ^a

PMCID: PMC2983746 PMID: 21580286

Abstract

The title compound, C₂₀H₁₇NO₅, was prepared by the reaction of 3-acetyl-2-oxo-2H-chromen-7-yl acetate with benzyloxyamine. The molecule adopts an E configuration with respect to the C=N double bond. The dihedral angles between the coumarin ring system, the phenyl ring and the C=N—O—C plane of the oxime unit are 35.83 (6), 35.8 (2) and 69.99 (15)°, respectively. In the crystal, a two-dimensional supramolecular network is assembled through weak intermolecular C—H⋯O hydrogen-bonding interactions.

Related literature

For the pharmacological applications of Schiff base compounds derived from coumarins, see: Jolanta et al. (2006 ▶); Kontogiorgis et al. (2006 ▶); Kontogiorgis & Hadjipavlou-Litina (2004 ▶); Nofal et al. (2000 ▶). For their use as dyes, fluorescent agents and as chemosensors, see: Kachkovski et al. (2004 ▶); Turki et al. (2006 ▶); Li et al. (2009 ▶).

Experimental

Crystal data

C₂₀H₁₇NO₅
M _r = 351.35
Triclinic,
a = 6.3901 (9) Å
b = 11.2413 (16) Å
c = 12.9298 (18) Å
α = 102.643 (2)°
β = 96.923 (2)°
γ = 101.860 (2)°
V = 873.5 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.25 × 0.20 × 0.18 mm

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.977, T _max = 0.983
5311 measured reflections
3792 independent reflections
2335 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.166
S = 1.09
3792 reflections
238 parameters
H-atom parameters constrained
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810003454/sj2717sup1.cif

e-66-0o511-sup1.cif^{(20.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810003454/sj2717Isup2.hkl

e-66-0o511-Isup2.hkl^{(185.9KB, 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⋯O5ⁱ	0.93	2.51	3.393 (3)	159
C18—H18⋯O5ⁱⁱ	0.93	2.67	3.552 (3)	160
C8—H8⋯O1ⁱⁱⁱ	0.93	2.65	3.397 (2)	138

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We are grateful to the Science and Technology Plan Project of Guangdong Province (No. 2008B010600008) for financial support.

supplementary crystallographic information

Comment

Coumarin-derived Schiff bases have attracted much attention due to their potential pharmacological applications as antitumor (Jolanta et al., 2006), anti-inflammatory (Kontogiorgis & Hadjipavlou-Litina 2004), antibacterial (Nofal et al., 2000) and antifungal agents (Kontogiorgis et al., 2006). In addition, they can also be used as dyes (Kachkovski et al., 2004), fluorescent agents (Turki et al., 2006) and as colorimetric chemosensors (Li et al., 2009). In our study of bioactive compounds, a series of coumarin-derived Schiff bases have been synthesized. Herein, we report the crystal structure of the title compound, Fig. 1, obtained by the reaction of 3-acetyl-2-oxo-2H-chromen-7-yl acetate with benzyloxy-amine.

The title molecule is composed of a coumarin core with acetoxyl and benzyloxyiminoethyl substituents. The dihedral angles between the coumarin ring system, the phenyl ring and the C=N—O—C plane of the oxime unit are 35.83 (6)°, 35.8 (2) ° and 69.99 (15) °, respectively. The benzyloxyiminoethyl and coumarin systems are located on opposite sides of the C=N double bond plane, therefor the molecule presents an E configuration. In the crystal structure, intermolecular C6—H6···O5 hydrogen bonding interactions (Table 1) assemble a two-dimensional supramolecular layer as shown in Fig. 2. Additional weak C8—H8···O1 and C18—H18···O5 contacts are also observed. The overall crystal packing is shown in Fig. 3.

Experimental

A solution of benzyloxy-amine hydrochloride (2 mmol) in ethanol (10 ml) was added to a solution of 3-acetyl-2-oxo-2H-chromen-7-yl acetate (1 mmol) in ethanol (10 ml) at room temperature, the solution pH was then maintained at a value of 7 by the addition of sodium hydroxide. The reaction mixture was refluxed for 5 h at 353 K (monitored by TLC). After completion of the reaction, the reaction solution was purified by column chromatography (ethyl acetate: petroleum ether = 2:3). The eluate was evaporated to give the title compound (286 mg, yield: 81.5%). Single crystals suitable for X-ray analysis were obtained by recrystallization from DMSO, m.p. 426 K. ESI-MS (m/z): 352 (M+1); Analysis calculated for C₂₀H₁₇NO₅: C 68.37%, H 4.88%, N 3.99%; Found: C 68.54%, H 4.32%, N 3.78%.