Ethyl 3-[2-(3,4-dimeth­oxy­benz­yl)-1-phenyl­sulfonyl-1H-indol-3-yl]acrylate chloro­form hemisolvate

M Thenmozhi; T Kavitha; V Dhayalan; A K Mohanakrishnan; M N Ponnuswamy

doi:10.1107/S1600536811017740

. 2011 May 20;67(Pt 6):o1460–o1461. doi: 10.1107/S1600536811017740

Ethyl 3-[2-(3,4-dimethoxybenzyl)-1-phenylsulfonyl-1H-indol-3-yl]acrylate chloroform hemisolvate

M Thenmozhi ^a, T Kavitha ^a, V Dhayalan ^b, A K Mohanakrishnan ^b, M N Ponnuswamy ^a,^*

PMCID: PMC3120582 PMID: 21754833

Abstract

In the title compound, C₂₈H₂₇NO₆S·0.5CHCl₃, the ethyl acrylate substituent adopts an extented conformation with all torsion angles close to 180°. The chloroform solvent molecule is disordered across an inversion centre and is therefore half occupied. The molecular packing is controlled by intermolecular C—H⋯O interactions.

Related literature

For general background to indoles, see: Hu et al. (2005 ▶); Nieto et al. (2005 ▶); Mathiesen et al. (2005 ▶); Olgen & Nebioglu (2002 ▶). For the sulfonyl moiety, see: Bassindale (1984 ▶). For hybridization, see: Beddoes et al. (1986 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₈H₂₇NO₆S·0.5CHCl₃
M _r = 565.25
Triclinic,
a = 10.2154 (3) Å
b = 12.0504 (4) Å
c = 12.6310 (4) Å
α = 70.602 (2)°
β = 69.613 (1)°
γ = 77.056 (2)°
V = 1364.39 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 293 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker Kappa APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.913, T _max = 0.941
38797 measured reflections
10612 independent reflections
7709 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.189
S = 1.04
10612 reflections
364 parameters
27 restraints
H-atom parameters constrained
Δρ_max = 0.73 e Å⁻³
Δρ_min = −0.46 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: SHELXS97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811017740/bt5508sup1.cif

e-67-o1460-sup1.cif^{(30.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811017740/bt5508Isup2.hkl

e-67-o1460-Isup2.hkl^{(518.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811017740/bt5508Isup3.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
C15—H15⋯O4ⁱ	0.93	2.53	3.411 (3)	159
C24—H24B⋯O7ⁱⁱ	0.96	2.51	3.461 (2)	169
C24—H24A⋯O7ⁱⁱⁱ	0.96	2.52	3.367 (3)	147
C30—H30A⋯O3^iv	0.96	2.59	3.429 (7)	146
C30—H30A⋯O4^iv	0.96	2.55	3.424 (7)	151

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

Acknowledgments

MT thanks the UGC for financial support in the form of a Research Fellowship in Science for Meritorious Students.

supplementary crystallographic information

Comment

Carboxylic acid indoles act as inhibitors of plasminogen activator inhibitor-1 (Hu et al., 2005). The benzenesulfonamide group attached to the indole ring exhibit significant biological activities, such as antibacterial etc., (Nieto et al., 2005). Also, the indole derivatives are identified as the molecules which interfere with a G protein-independent signaling pathway of the CRTH2 receptor (Mathiesen et al.,2005). N-substituted indole carboxylic acid esters have been prepared as possible cyclo-oxygenase-2 (COX-2) enzyme inhibitors (Olgen & Nebioglu, 2002).

Fig.1 shows the ORTEP plot of the title compound. The indole moiety is planar with the maximum deviation of -0.033 (2)Å and 0.028 (2)Å for atoms C5 and C7, respectively. The indole ring system is oriented equatorially to the phenyl sulfonyl ring [dihedral angle = 78.18 (6)°]. The O—S—O and N—S—C angles [See Table1] deviate significantly from their ideal value due to the Thrope-Ingold effect (Bassindale, 1984). The dimethoxybenzyl group is also equatorially oriented to the planar indole ring, which can be observed from the dihedral angle [78.04 (4)°].

The ethyl acrylate group substituted at C3 position of the indole ring takes up an extented conformation which is evident from the torsion angle values [C25—C26—C27—O8 =] -179.10 (16)°; [C25—C26—C27- O7 =] 1.8 (3)°; [C26—C27—O8—C28 =] 179.8 (2)°; [C29—C28—O8—C27 =] 179.7 (2)°. The sum of the bond angles around N1[359.37°] shows that atom N1 exhibits sp² hybridization (Beddoes et al., 1986). The chloroform solvent is disordered across inversion centre with the site occupancies of 0.5 for each.

The molecular packing is controlled by intra and intermolecular C—H···O interactions in addition to van der Waals forces (Table 2). Atom H15 of C15 form an intermolecular hydrogen bonding with atom O4, leading to a C11 linear chains (Bernstein et al., 1995) with C—H···O type of interactions running along a-axis. The intermolecular interaction C24—H24A···O7 leads to R₂²(13) dimers, which are connected through C24—H24B···O7 interaction as closed loops running along c-axis. Intermolecular bifurcated C—H···O hydrogen bonds involving the two oxygen atoms of the dimethoxybenzyl group and the hydrogen atom of the chloroform, solvent generates R₁²(5) ring motif (Fig.2).

Experimental

To a solution of (E)-Ethyl 3-(2-(bromomethyl)-1-(phenylsulfonyl)-1H-indol-3-yl) acrylate (0.3 g, 0.66 mmol) in dry DME (10 ml), ZnBr₂ (0.3 g, 1.3 mmol), K₂CO₃ (0.18 g, 1.33 mmol) and veratrole (0.11 g, 0.79 mmol) were added. The reaction mixture was then refluxed for 12hrs under N₂ atmosphere. The solvent was removed and the reaction mixture was quenched with ice-water (100 mL) containing 2 mL of conc.HCl. It was then extracted with chloroform (20 mL) and dried (Na₂SO₄). Removal of the solvent followed by crystallization from methanol afforded the product as pale yellow crystals.