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

Xiao-Wei Tang; Tie-Liang Zhu; Hong Chen; Dan-Li Tian; Shao-Yu Shi

doi:10.1107/S1600536811012815

. 2011 Apr 16;67(Pt 5):o1158. doi: 10.1107/S1600536811012815

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

Xiao-Wei Tang ^a, Tie-Liang Zhu ^b, Hong Chen ^b,^c,^*, Dan-Li Tian ^a, Shao-Yu Shi ^a

PMCID: PMC3089210 PMID: 21754466

Abstract

In the title compound, C₁₆H₂₀N₂O₃, the crystal packing is stabilized by weak π–π stacking interactions [centroid–centroid distances = 3.577 (9) and 3.693 (9) Å] and intermolecular C—H⋯O and N—H⋯O hydrogen-bond interactions. The C atoms of the N-isopropyl group are disordered over two sets of sites with occupancies of 0.61(3) and 0.39(3).

Related literature

For the biological activity of the title compound and its derivatives, see: Souli et al. (2008 ▶); Chai et al. (2006 ▶); Radwan et al. (2007 ▶); Karthikeyan et al. (2009 ▶). For the preparation, see: Bacher et al. (2001 ▶). For bond lengths and angles in similar structures, see: Feng et al. (2008 ▶); Sonar et al. (2006 ▶).

Experimental

Crystal data

C₁₆H₂₀N₂O₃
M _r = 288.34
Orthorhombic,
a = 11.593 (3) Å
b = 9.182 (2) Å
c = 27.796 (6) Å
V = 2958.8 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 113 K
0.30 × 0.24 × 0.10 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.974, T _max = 0.991
25486 measured reflections
3527 independent reflections
3320 reflections with I > 2σ(I)
R _int = 0.053

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.133
S = 1.12
3527 reflections
204 parameters
39 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); 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 I, global. DOI: 10.1107/S1600536811012815/hg5020sup1.cif

e-67-o1158-sup1.cif^{(20.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811012815/hg5020Isup2.hkl

e-67-o1158-Isup2.hkl^{(173.1KB, 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—H3A⋯O2ⁱ	0.95	2.54	3.4874 (17)	172
N2—H2B⋯O3ⁱⁱ	0.894 (19)	2.149 (19)	2.9933 (17)	157.2 (16)

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

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 30873363), the Program of the Science Foundation of Tianjin (08JCYBJC070000) and the Major Program of the Science Foundation of Tianjin (09ZCKFSH01700).

supplementary crystallographic information

Comment

Indole and their derivatives are well known as substances with biologically activity such as anti-cancer (Souli et al., 2008), anti-virus (Chai et al., 2006), anti-tubercular (Karthikeyan et al., 2009), and anti-inflammatory (Radwan et al., 2007). In recent years, our recent study is paying attention to synthesize different kinds of indole derivatives with improved bioactivities. In this paper, we reported the crystal structure of the title compound.

In title compound, C₁₆H₂₀N₂O₃, bond lengths and angles are normal and in good agreement with those reported previously (Feng et al., 2008; Sonar, et al., 2006). π—π interactions are indicated by the short distance (Cg1···Cg2 distance of 3.693 (9) Å, Cg2···Cg2 distance of 3.577 (9)Å symmetry code: 1 - x,1 - y,-z) between the centroids of the pyrrole ring (N1/C1/C6—C8) (Cg1) and benzene ring C1—C6 (Cg2) (Table 1). There are weaker C—H···O and N—H···O intermolecular interactions, which stabilized the structure (Table 1).

Experimental

The target compound was synthesized by three steps. Under ice bath, DMF solution of 5-methoxy indole was added dropwise to DMF solution of NaH 0.5 h later, ethyl bromide was added. The reaction solvent add into ice water, and the compound is separated from the liquid after stirring. Oxalyl chloride was added dropwise to the 1-ethyl-methoxy indole in dry ether, 1-ethyl-methoxy indole-3-yl-glyoxyl chloride which was the crude product, propan-2-amine, two drops of triethylamine were in dry dichloromethane. The reaction mixture was washed with water and dried over Na₂SO₄ and concentrated in vacuo (Bacher et al., 2001). The residue was resolved in a methanol solution. Slow evaporatin over two week at room temperature gave light-yellow crystals suitable for X-ray analysis.