2-(6-Methyl-2,3,4,9-tetra­hydro-1H-carbazol-1-yl­idene)propane­dinitrile

M Sekar; R Velmurugan; A Chandramohan; P Ramesh; M N Ponnuswamy

doi:10.1107/S160053681104654X

. 2011 Nov 12;67(Pt 12):o3270. doi: 10.1107/S160053681104654X

2-(6-Methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)propanedinitrile

M Sekar ^a, R Velmurugan ^a, A Chandramohan ^a, P Ramesh ^b, M N Ponnuswamy ^b,^*

PMCID: PMC3238928 PMID: 22199777

Abstract

In the title compound, C₁₆H₁₃N₃, the cyclohexene ring adopts a sofa conformation. An intramolecular N—H⋯N hydrogen bond generates an S(7) ring motif. In the crystal, the molecules are linked by pairs of N—H⋯N interactions, forming centrosymmetric dimers with an R ₂ ²(14) motif.

Related literature

For the biological activity of carbazole derivatives, see: 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 ▶). 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

C₁₆H₁₃N₃
M _r = 247.29
Triclinic,
a = 7.6396 (9) Å
b = 8.4381 (8) Å
c = 10.8967 (13) Å
α = 88.395 (6)°
β = 71.392 (7)°
γ = 71.217 (6)°
V = 628.08 (12) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.17 × 0.16 × 0.15 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.986, T _max = 0.988
12507 measured reflections
3692 independent reflections
2815 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.154
S = 1.03
3692 reflections
177 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.19 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/S160053681104654X/bt5683sup1.cif

e-67-o3270-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681104654X/bt5683Isup2.hkl

e-67-o3270-Isup2.hkl^{(181KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681104654X/bt5683Isup3.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⋯N16	0.86 (2)	2.59 (2)	3.3099 (17)	141.4 (16)
N1—H1⋯N16ⁱ	0.86 (2)	2.49 (2)	3.2150 (17)	142.8 (16)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Solid State Unit, Indian Institute of Science, Bangalore, India, for the data collection.

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). 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). 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. 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=0.330 (1) Å, q₃ = 0.262 (1) Å, φ₂ = 168.7 (2)° and Δ_s(C2 & C5)= 8.6 (2)°. The sum of the bond angles around N1 [359.8°] is in accordance with sp² hybridization. The bond lengths and bond angles of (C15—N16) 1.148 (2) Å, (C17—N18) 1.145 (2) Å, (C14—C15—N16) 178.8 (2)° and (C14—C17—N18) 178.6 (2)° show linear character of the cyano group, a feature observed in carbonitrile compounds.

The crystal packing reveals that symmetry-related molecules are linked by N—H···N interactions. The intramolecular N1—H1···N16 hydrogen bond generates a S(7) ring motif. The molecules at (x, y, z) and (2 - x, -1 - y, 1 - z) are linked by N1—H1···N16 hydrogen bonds into cyclic centrosymmetric R₂²(14) dimer.

Experimental

A mixture of 6-methyl-1-oxo-1,2,3,4-tetrahydrocarbazole (7.5 mmol), and melanonitrile (7.5 mmol), ammonium acetate (0.57 g, 8.125 mmol) and acetic acid (1.5 ml, 24.75 mmol) in 12.5 ml of toluene was stirred at 105°C for 5 h. On cooling the precipitate that formed was filtered off, washed with hexane (20 ml) and dried at 100°C to give a crude product of 6-Methyl-2-(1,2,3,4- tetrahydro-9H-carbazol-1-ylidene)propanedinitrile.The crystals of the title compound suitable for single XRD analysis were obtained by the slow evaporation method by using dichloroethane as solvent at room temperature.