6-Bromo-2-(3-phenyl­allyl­idene)-2,3,4,9-tetra­hydro-1H-carbazol-1-one

R Velmurugan; M Sekar; A V Vijayasankar; P Ramesh; M N Ponnuswamy

doi:10.1107/S1600536811046563

. 2011 Nov 12;67(Pt 12):o3269. doi: 10.1107/S1600536811046563

6-Bromo-2-(3-phenylallylidene)-2,3,4,9-tetrahydro-1H-carbazol-1-one

R Velmurugan ^a, M Sekar ^a, A V Vijayasankar ^b, P Ramesh ^c, M N Ponnuswamy ^c,^*

PMCID: PMC3238927 PMID: 22199776

Abstract

Molecules of the title compound, C₂₁H₁₆BrNO, are linked through pairs of N—H⋯O intermolecular hydrogen bonds into centrosymmetric R ₂ ²(10) dimers. One of the C atoms of the cyclohex-2-enone ring is disordered with refined occupancies of 0.61 (2) and 0.39 (2).

Related literature

For the biological activity of carbazole derivatives, see: Shufen et al. (1995 ▶); Magnus et al. (1992 ▶); Abraham (1975 ▶); Saxton (1983 ▶); Phillipson & Zenk (1980 ▶); Bergman & Pelcman (1990 ▶); Bonesi et al. (2004 ▶); Chakraborty et al. (1965 ▶); Kirtikar & Basu (1933 ▶); Chakraborty et al. (1973 ▶); Knolker & Reddy, 2002 ▶. For puckering parameters, see: Cremer & Pople (1975 ▶). For asymmetry parameters, see: Nardelli (1983 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₁H₁₆BrNO
M _r = 378.26
Monoclinic,
a = 17.3682 (7) Å
b = 14.9974 (8) Å
c = 6.6861 (3) Å
β = 92.226 (2)°
V = 1740.27 (14) Å³
Z = 4
Mo Kα radiation
μ = 2.37 mm⁻¹
T = 293 K
0.20 × 0.17 × 0.16 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.629, T _max = 0.685
16684 measured reflections
4319 independent reflections
2158 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.137
S = 0.97
4319 reflections
231 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (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 datablock(s) global, I. DOI: 10.1107/S1600536811046563/bt5677sup1.cif

e-67-o3269-sup1.cif^{(26.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811046563/bt5677Isup2.hkl

e-67-o3269-Isup2.hkl^{(211.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811046563/bt5677Isup3.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⋯O1ⁱ	0.82 (3)	2.02 (3)	2.813 (3)	161 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Solid State Unit, Indian Institute of Science, Bangalore, India, for the data collection and Dr A. Chandramohan, Post Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore, for his valuable suggestions.

supplementary crystallographic information

Comment

Carbazole alkaloids obtained from naturally occurring sources have been the subject of extensive research, mainly because of their widespread applications in traditional medicine (Bergman & Pelcman, 1990; Bonesi et al., 2004; Chakraborty et al., 1965; Kirtikar & Basu, 1933). Aminocarbazoles are widely used as intermediates for the preparation of carbazole-based synthetic dyes, agrochemicals, pharmaceuticals and light-sensitive materials (Shufen et al., 1995). Tetrahydrocarbazole systems are present in the framework of a number of indole-type alkaloids of biological interest (Magnus et al., 1992; Abraham, 1975; Saxton, 1983; Phillipson et al., 1980). These types of compounds possess significant antibiotic, anti-carcinogenic, antiviral and anti-inflammatory properties (Chakraborty et al., 1973). The chemists have been attracted towards these compounds due to their biological activities and potential applications as pharmacological agents (Knolker & Reddy, 2002). Against this background and to ascertain the molecular structure and conformation, the X-ray crystal structure determination of the title compound has been carried out.

The ORTEP plot of the molecule is shown in Fig. 1. One of the C atoms of the cyclohexane ring is disordered with refined occupancies of 0.61 (2) and 0.39 (2). The disordered position of C10B in the cyclohexane ring in the carbazole ring system adopts envelope conformation with the puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) are: q₂=0.242 (7) Å, q₃ = 0.171 (6) Å, φ₂ = 117.3 (13)° and Δ_s(C10B & C13)= 1.5 (5)°. The sum of the bond angles around N1 [358.3°] is in accordance with sp² hybridization.

The crystal packing reveals that symmetry-related molecules are linked through N—H···O intermolecular hydrogen bonds into cyclic centrosymmetric R₂²(10) dimers.

Experimental

The mixed aldol condensation reaction of 6-bromo-1-oxo-1,2,3, 4-tetrahydrocarbazole reacted with cinnamaldehyde in the presence of alcoholic KOH, afforded a single product, substituted 6-Bromo-2-(3-phenyl-allylidene) -2,3,4,9-tetrahydro-carbazol-1-one. This was purified by using column chromatography over silica gel (mesh 60–80). During elution of the column with petroleum ether (60–80°C) and ethyl acetate [1:2] mixture, a yellowish solid was obtained. It was recrystallized from the solvent mixture ethyl acetate and acetone (8:2).