Ethyl 2-amino-4-(3-chloro­phen­yl)-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxyl­ate

Xiao Hu; Song Lei; Chang-Sheng Yao

doi:10.1107/S160053680901753X

. 2009 May 20;65(Pt 6):o1324. doi: 10.1107/S160053680901753X

Ethyl 2-amino-4-(3-chlorophenyl)-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxylate

Xiao Hu ^a,^*, Song Lei ^b,^c, Chang-Sheng Yao ^b,^c

PMCID: PMC2969697 PMID: 21583179

Abstract

The title molecule, C₂₂H₁₆ClNO₅, was obtained by the reaction of (E)-ethyl 3-(3-chlorophenyl)-2-cyanoacrylate and 2-hydroxynaphthalene-1,4-dione catalysed by triethylamine in ethanol. In the crystal structure, the chlorobenzene ring makes a dihedral angle of 88.63 (4)° with the fused ring system. The six-membered ring formed by an intramolecular N—H⋯O hydrogen bond is almost planar. The crystal packing is stabilized by N—H⋯O hydrogen bonds.

Related literature

For the antitumor activity of 4H-naphtho[2,3-b]pyran-5,10-dione derivatives, see: Fujimoto (2007 ▶); Perchellet et al. (2001 ▶); Zhan et al. (2007 ▶). For natural products containing H-naphtho[2,3-b]pyran-5,10-dione, see: Jassbi et al. (2004 ▶); Rodriguez et al. (2003 ▶).

Experimental

Crystal data

C₂₂H₁₆ClNO₅
M _r = 409.81
Triclinic,
a = 6.1175 (17) Å
b = 10.021 (3) Å
c = 15.967 (5) Å
α = 84.840 (13)°
β = 87.714 (12)°
γ = 67.429 (8)°
V = 900.2 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 113 K
0.32 × 0.30 × 0.20 mm

Data collection

Rigaku Saturn diffractometer
Absorption correction: multi-scan (Jacobson, 1998 ▶) T _min = 0.924, T _max = 0.952
11338 measured reflections
4261 independent reflections
3031 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.097
S = 1.01
4261 reflections
272 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.45 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2002 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; 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 global, I. DOI: 10.1107/S160053680901753X/hg2512sup1.cif

e-65-o1324-sup1.cif^{(21.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680901753X/hg2512Isup2.hkl

e-65-o1324-Isup2.hkl^{(208.8KB, 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
N1—H1⋯O4	0.898 (18)	2.049 (18)	2.6827 (17)	126.5 (15)
N1—H2⋯O2ⁱ	0.880 (19)	2.12 (2)	2.9913 (17)	170.2 (18)

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The derivatives of 4H-naphtho[2,3-b]pyran-5,10-dione have antitumor activities (Fujimoto, 2007; Zhan et al., 2007; Perchellet et al., 2001). Besides, some natural products also contain this moiety (Rodriguez et al., 2003; Jassbi et al., 2004). In order to develop new potential antitumor chemicals, a series of novel 4H-naphtho[2,3-b]pyran-5,10-dione derivatives based on the scaffolds of natural products have been synthesized. However, to the best of our knowledge, there are no reports on the crystal structure of these compounds. Determination of the molecular structure is crucial to the study of the structure and activity relationship. Here we report the crystal structure of the title compound, (I).

The molecular structure of (I) is shown in Fig. 1. It consists of five rings, considering the six-membered ring formed by the intramolecular N1—H1···O4 hydrogen bond (Table 1). The dihedral angles between the neighbouring rings show that the naphthalene ring and the pyran ring in an envelope conformation are almost coplanar. The phenyl ring bonded to the pyrans ring is almost perpendicular to the fused ring, for the dihedral angle is 88.63 (4)°. In the molecular structure, the crystal packing is stabilized N1—H2···O2 intermolecular hydrogen bonds. (Figs.2, Table 1)

Experimental

The title compound was synthesized by the reaction of (E)-ethyl 3-(3-chlorophenyl)-2-cyanoacrylate (1 mmol) and 2-hydroxynaphthalene-1,4-dione (1 mmol) catalyzed by Et₃N in 15 ml ethanol at reluxing temperature. After cooling, the solvent was removed at reduced pressure and the residue was washed with water and recrystallized from ethanol, which gave single crystals suitable for X-ray diffraction.