5-(1H-Indol-3-yl­methyl­idene)-2,2-di­methyl-1,3-dioxane-4,6-dione

Yu-Xin He; Jin-Wei Wu; Rong-Sheng Tong; Jin-Qi Li; Jian-You Shi

doi:10.1107/S1600536811023944

. 2011 Jun 30;67(Pt 7):o1835. doi: 10.1107/S1600536811023944

5-(1H-Indol-3-ylmethylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione

Yu-Xin He ^a, Jin-Wei Wu ^a, Rong-Sheng Tong ^b, Jin-Qi Li ^b, Jian-You Shi ^b,^*

PMCID: PMC3152020 PMID: 21837202

Abstract

In the title compound, C₁₅H₁₃NO₄, the conjugated double-bond system between the two rings adopts a cis configuration and there is an intramolecular indole–ketone C—H⋯O interaction. The indole N—H group forms an intermolecular hydrogen bond with a ketone O-atom acceptor, giving a chain structure along the ab direction. The O-heterocyclic ring adopts a boat conformation and makes a dihedral angle of 16.72 (6)° with the indole ring system.

Related literature

For a similar structure, see: He et al. (2011 ▶).

Experimental

Crystal data

C₁₅H₁₃NO₄
M _r = 271.26
Triclinic,
a = 7.0228 (4) Å
b = 8.7021 (5) Å
c = 11.5668 (9) Å
α = 80.281 (6)°
β = 76.362 (6)°
γ = 70.662 (5)°
V = 645.02 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 150 K
0.30 × 0.25 × 0.20 mm

Data collection

Oxford Diffraction Xcalibur Eos CCD-detector diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.969, T _max = 1.000
5351 measured reflections
2632 independent reflections
2098 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.099
S = 1.04
2632 reflections
183 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: OLEX2.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811023944/zs2118sup1.cif

e-67-o1835-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811023944/zs2118Isup2.hkl

e-67-o1835-Isup2.hkl^{(129.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811023944/zs2118Isup3.cml

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⋯O4ⁱ	0.88	2.02	2.8285 (16)	152
C8—H8⋯O3	0.95	2.17	2.8492 (19)	128

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Mr Zhi-Hua Mao of Sichuan University for the X-ray data collection. This study was supported by the Research Fund of the Key Laboratory of TCM Biotechnology (Xihua University).

supplementary crystallographic information

Comment

The title compound C₁₅H₁₃NO₄ (I) is a key reaction intermediate which can be used to synthesize the 4(1H)quinolone derivatives via thermolysis. These compounds can be used as precursors for the synthesis of anti-malarial and, anticancer agents.

In (I) (Fig. 1) the conjugated double bond system between the two rings adopts a cis configuration and there is an intramolecular indole C—H···O_ketone interaction. The indole N—H group forms an intermolecular hydrogen bond with a ketone O acceptor (Table 1), giving a one-dimensional chain structure.

Experimental

A mixture of 2,2-dimethyl-1,3-dioxane-4,6-dione (1.44 g, 0.01 mol) and methyl orthoformate (1.27 g, 0.012 mol) was heated to reflux for 0.5 h, after which a solution of 1H-indole (1.17 g, 0.01 mol) in ethanol (20 mL) was added. The mixture was refluxed for a further 3.5 h and then poured into cold water after which the product was removed by filtration. Yellow crystals of (I) were obtained after 7 days from the room temperature evaporation of a solution in CH₂Cl₂–methanol.