3-Ethenyl-1-(4-methyl­phenyl­sulfon­yl)-1H-indole

Julio Zukerman-Schpector; Glaudeston D Wulf; Hélio A Stefani; Stanley N S Vasconcelos; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812021526

. 2012 May 19;68(Pt 6):o1829–o1830. doi: 10.1107/S1600536812021526

3-Ethenyl-1-(4-methylphenylsulfonyl)-1H-indole

Julio Zukerman-Schpector ^a,^*, Glaudeston D Wulf ^a, Hélio A Stefani ^b, Stanley N S Vasconcelos ^b, Seik Weng Ng ^c,^d, Edward R T Tiekink ^c

PMCID: PMC3379403 PMID: 22719601

Abstract

Two independent but very similar molecules comprise the asymmetric unit of the title compound, C₁₇H₁₅NO₂S. The molecules have L-shapes with the dihedral angles between the fused-ring system (r.m.s. deviations = 0.036 and 0.019 Å, respectively) and the benzene ring being almost the same, i.e. 82.98 (12) and 84.46 (13)°, respectively. The terminal ethenyl group is almost coplanar with the ring to which it is connected [C—C—C—C torsion angles = −173.7 (4) and −171.7 (4)°, respectively]. Supramolecular arrays parallel to (-124) stabilized by C—H⋯O and C—H⋯π interactions feature in the crystal packing.

Related literature

For background to the biological activity of indoleamine 2,3-dioxygenase and inhibitors, see: Rohrig et al. (2010 ▶); Munn & Mellor (2007 ▶); Muller et al. (2005 ▶). For related structures, see: Seshadri et al. (2002 ▶); Senthil Kumar et al. (2006 ▶); Chakkaravarthi et al. (2008 ▶). graphic file with name e-68-o1829-scheme1.jpg

Experimental

Crystal data

C₁₇H₁₅NO₂S
M _r = 297.37
Triclinic,
a = 9.8809 (4) Å
b = 10.0167 (3) Å
c = 15.5280 (5) Å
α = 83.687 (3)°
β = 77.864 (3)°
γ = 88.769 (3)°
V = 1493.41 (9) Å³
Z = 4
Cu Kα radiation
μ = 1.95 mm⁻¹
T = 100 K
0.35 × 0.30 × 0.25 mm

Data collection

Agilent SuperNova (Dual, Cu at zero) diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.548, T _max = 0.641
11566 measured reflections
6103 independent reflections
5505 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.069
wR(F ²) = 0.185
S = 1.02
6103 reflections
381 parameters
H-atom parameters constrained
Δρ_max = 0.94 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶), QMol (Gans & Shalloway, 2001 ▶), DIAMOND (Brandenburg, 2006 ▶) and MarvinSketch (ChemAxon, 2009 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812021526/hg5227sup1.cif

e-68-o1829-sup1.cif^{(27.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812021526/hg5227Isup2.hkl

e-68-o1829-Isup2.hkl^{(298.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812021526/hg5227Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1, Cg2 and Cg3 are the centroids of the C1–C6, N2–C25 and C18–C23 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯O2ⁱ	0.95	2.50	3.433 (4)	166
C20—H20⋯O2ⁱⁱ	0.95	2.52	3.373 (5)	149
C25—H25⋯O4ⁱⁱⁱ	0.95	2.48	3.406 (4)	166
C30—H30⋯Cg1^iv	0.95	2.77	3.617 (4)	149
C34—H34C⋯Cg2^v	0.98	2.95	3.525 (4)	119
C12—H12⋯Cg3^v	0.95	2.87	3.739 (3)	153
C15—H15⋯Cg3^v	0.95	2.86	3.638 (3)	140

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

Acknowledgments

We thank the Brazilian agencies: FAPESP (07/59404–2 to HAS), CNPq (300613/2007–5 to HAS and 306532/2009–3 to JZS) and CAPES (808/2009 to JZS) for financial support. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

Indoleamine 2,3-dioxygenase (IDO) is an enzyme that catalyses the degradation of the essential amino acid tryptophan. Elevated tryptophan catabolism mediated by IDO is associated with a wide variety of human cancers and cataract formation (Rohrig et al., 2010). It has also been shown that inhibition of IDO leads to an arrest in tumour growth (Munn & Mellor, 2007; Muller et al., 2005). As part of our on-going research targeted towards the synthesis of α- and β-hydroxy indols as potential IDO inhibitors, the title compound, (I), was synthesized and its crystal structure determined.

There are two independent molecules in the asymmetric unit of (I), Fig. 1, and as seen from the overlay diagram in Fig. 2, these are almost identical with the r.m.s. deviation being 0.1107 Å. The dihedral angles between the fused ring system (r.m.s. deviations = 0.036 and 0.019 Å for the N1- and N2-containing rings, respectively) and the benzene ring are almost the same, i.e. 82.98 (12) and 84.46 (13)°, respectively. The values found in similar structures are of 80.37 (8)° (Chakkaravarthi et al., 2008), 77.41 (5)° (Senthil Kumar et al., 2006) and 66.47 (15) °. (Seshadri et al., 2002). For each molecule, the terminal ethenyl group is almost co-planar to the ring to which it is connected as seen in the values of the C8—C7—C9—C10 and C25—C24—C26—C27 torsion angles of -173.7 (4) and -171.7 (4)°, respectively.

The crystal packing of (I) is sustained by C—H···O and C—H···π interactions, Table 1. These lead to supramolecular arrays parallel to (1 2 4), Fig. 2, which stack with no specific intermolecular interactions between them, Fig. 3.

Experimental

A solution of methyltriphenylphosphonium iodide (0.34 g, 0.84 mmol, 1.4 eq.) in THF (5 ml) at 273 K was poured into a two-necked round-bottomed flask under a nitrogen atmosphere and then under continuous stirring nBuLi (0.36 ml, 0.72 mmol,1.2 eq.) was added drop-wise at 195 K. The mixture was left in a water/ice bath for 20 min, then a solution of 1-tosyl-1-H-indol-carbaldehide (0.181 g) in THF (5 ml) was added. After stirring for another 20 min. the solution was warmed to room temperature and water added. The mixture was extracted with Et₂O, washed with NH₄Cl and dried under MgSO₄. The remaining solvent was removed under reduced pressure. Purification through flash chromatography with a solution of hexane and ethyl acetate in a 7:3 ratio give the pure product (yield = 62%). Crystals for X-ray analysis were obtained by slow evaporation from EtOAc held at 293 K; M.pt: 374–375 K.

NMR ¹H (CDCl₃, 300 MHz, p.p.m.): δ 7.99 (d, J = 8.2 Hz, 1H), 7.75 (d, J = 8.4 Hz, 2H), 7.72 (d, J = 8.3 Hz, 1H), 7.59 (s, 1H), 7.34–7.23 (m, 2H), 7.17 (d, J = 8,2 Hz, 2H), 6.75 (dd, J = 17.8 and 11.3 Hz, 1H), 5.78 (d, J = 17.8 Hz, 1H), 5.33 (d, J = 11,3 1H), 2.29 (s, 3H). NMR ¹³C (CDCl₃, 75 MHz, p.p.m.): δ 145.04, 135.55, 135.19, 129.91 (2 C), 129.04, 127.57, 126.85 (2 C), 124.92, 124.09, 123.53, 121.00, 120.43, 115.35, 113.76, 21.54.