2-(1-Ethyl-5-meth­oxy-1H-indol-3-yl)-N-(4-meth­oxy­phen­yl)-2-oxoacetamide

Li-Ting Chen; Yan-Ling Lu; Hong Chen; Jing Zhou

doi:10.1107/S1600536810054668

. 2011 Jan 12;67(Pt 2):o358. doi: 10.1107/S1600536810054668

2-(1-Ethyl-5-methoxy-1H-indol-3-yl)-N-(4-methoxyphenyl)-2-oxoacetamide

Li-Ting Chen ^a, Yan-Ling Lu ^b, Hong Chen ^c, Jing Zhou ^a,^*

PMCID: PMC3051647 PMID: 21523037

Abstract

The title compound, C₂₀H₂₀N₂O₄, crystallizes with four independent molecules in the asymmetric unit. In the molecules, the dihedral angles between the benzene rings and indole mean planes are 24.5 (1), 22.5 (1), 8.8 (1) and 13.9 (1)°. In the crystal, intermolecular N—H⋯O hydrogen bonds are present between the imino groups and the adjacent carbonyl groups. π–π stacking is also observed with a centroid–centroid distance between nearly parallel pyrrole rings of 3.745 (3) Å.

Related literature

For the biological activity of the title compound and related compounds, see: Souli et al. (2008 ▶); Liu et al. (2007 ▶); Chai et al. (2006 ▶); Radwan et al. (2007 ▶); Karthikeyan et al. (2009 ▶). For the preparation, see: Bacher et al. (2001 ▶).

Experimental

Crystal data

C₂₀H₂₀N₂O₄
M _r = 352.38
Monoclinic,
a = 8.3622 (17) Å
b = 35.073 (7) Å
c = 12.280 (3) Å
β = 105.40 (3)°
V = 3472.1 (14) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 153 K
0.20 × 0.14 × 0.08 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
33298 measured reflections
7700 independent reflections
6293 reflections with I > 2σ(I)
R _int = 0.075

Refinement

R[F ² > 2σ(F ²)] = 0.062
wR(F ²) = 0.144
S = 1.09
7700 reflections
966 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810054668/xu5111sup1.cif

e-67-0o358-sup1.cif^{(50.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810054668/xu5111Isup2.hkl

e-67-0o358-Isup2.hkl^{(376.7KB, 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
N2—H2⋯O6ⁱ	0.88 (3)	2.17 (3)	2.967 (5)	150 (4)
N4—H4C⋯O2ⁱⁱ	0.85 (5)	2.44 (5)	3.245 (5)	159 (5)
N6—H6⋯O14ⁱⁱⁱ	0.96 (5)	2.30 (5)	3.196 (5)	154 (4)
N8—H8⋯O10^iv	0.92 (3)	2.08 (4)	2.936 (5)	155 (7)

Open in a new tab

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

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 30873363), the Great Program of the Science Foundation of Tianjin (09ZCKFNC01200) and the Program of the Science Foundation of Tianjin City, China (08JCYBJC070000).

supplementary crystallographic information

Comment

The indole substructure is a basic core unit for numerous physiologically active natural and synthetic molecule, hence indole and its derivatives always act as lead compounds in many pharmaceutical with variety of biological activity such as anti-cancer (Souli et al., 2008), anti-thrombosis (Liu et al., 2007), anti-tubercular (Karthikeyan et al., 2009), anti-virus(Chai et al., 2006), and anti-inflammatory(Radwan et al., 2007).

In this work, the title compound (I), C₂₀H₂₀N₂O₄, (Fig.1), has been synthesized. In an asymmetric unit of (I) four molecules can be observed. (I) crystallizes in the Monoclinic,P2(1) space group, a = 8.3622 (17) Å, b = 35.074 (7) Å, c = 12.280 (3) Å, β = 105.40 (3)°. The dihedral angle between the anisole and indole planes is 24.5 (1)°, 22.5 (1)°, 8.8 (1)° and 13.9 (1)°. N atoms in the molecule act as hydrogen-bond donors to O atoms in the adjacent molecules forming intermolecular N2—H2···O6 (symmetry code: -x + 1, y - 1/2, -z + 1), N4—H4C···O2 (symmetry code: -x + 1, y + 1/2, -z + 1), N6—H6···O14 (symmetry code: x, y, z + 1) and N8—H8···O10 (symmetry code: x, y, z - 1) hydrogen bonds, and these N—H···O hydrogen bonds stabilize the crystal structure.π-π interactions between the indole rings are also present, and the centroid-centroid distance between the adjacent pyrrole rings is 3.745 (1) Å. The parallel slipped π-π interactions between the indole rings further consolidate (I) into the three-dimensional supramolecular architecture.

Perspective drawing with the atomic numbering scheme is showed in Figure1. The N—H···O hydrogen bonds are illustrated in Figure 2.

Experimental

The target compound was synthesized following the method described by Bacher et al. (2001). Reaction of treated 5-methoxyl-indole (by NaH) with bromoethane in dimethylformamide yielded 1-ethyl-5-methoxy-1H-indole in 85% yield. Treatment of 1-ethyl-5-methoxy-1H-indole with oxalylchloride in dry ether as solvent, the target compound was synthesized by the reaction of 2-(1-ethyl-5-methoxy-1H-indol-3-yl)-2-oxoacetyl chloride with 4-methoxybenzenamine in dry DCM in the presence of triethylamine. Yellow prism crystals were obtained by slow evaporation from a methanol solution of product at room temperature.