9-Ethyl-2,3-dihydro-9H-carbazol-4(1H)-one

S Murugavel; G Ganesh; A Subbiah Pandi; Ramalingam Murugan; S Sriman Narayanan

doi:10.1107/S1600536808024318

. 2008 Aug 6;64(Pt 9):o1681. doi: 10.1107/S1600536808024318

9-Ethyl-2,3-dihydro-9H-carbazol-4(1H)-one

S Murugavel ^a, G Ganesh ^b, A Subbiah Pandi ^c,^*, Ramalingam Murugan ^d, S Sriman Narayanan ^d

PMCID: PMC2960498 PMID: 21201671

Abstract

In the title compound, C₂₈H₃₀N₂O₂, the cyclohexene ring system adopts a sofa conformation. The crystal structure is stabilized by C—H⋯O interactions between methyl H atoms of the ethyl substituents and the O atoms of carbonyl groups of adjacent molecules, and by an intermolecular carbonyl–carbonyl interactions [3.207 (2) Å]

Related literature

For related literature, see: Abraham (1975 ▶); Govindasamy et al. (1999 ▶); Hewlins et al. (1984 ▶); Kansal et al. (1986 ▶); Mi et al. (2003 ▶); Nardelli (1983 ▶); Phillipson & Zenk (1980 ▶); Saxton (1983 ▶); Allen et al. (1998 ▶); Cremer & Pople (1975 ▶); Mohanakrishnan & Srinivasasan (1995 ▶ ▶, 1995 ▶ ▶).

Experimental

Crystal data

C₁₄H₁₅NO
M _r = 213.27
Monoclinic,
a = 8.3742 (6) Å
b = 17.033 (1) Å
c = 8.6083 (5) Å
β = 116.432 (3)°
V = 1099.51 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (2) K
0.21 × 0.19 × 0.17 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: none
11070 measured reflections
2334 independent reflections
1898 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.105
S = 1.03
2334 reflections
146 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2004 ▶); 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, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808024318/lx2064sup1.cif

e-64-o1681-sup1.cif^{(17.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808024318/lx2064Isup2.hkl

e-64-o1681-Isup2.hkl^{(112.4KB, 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
C14—H14A⋯O1ⁱ	0.96	2.60	3.549 (2)	170

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are greatful to Dr S. Pandi, Head of the Department of Physics, Presidency College (Autonomous), Chennai, for providing the necessary facilities. Dr Babu Varghese, SAIF, IIT, Madras, India, is thanked for collecting the X-ray intensity data.

supplementary crystallographic information

Comment

Carbazole derivatives exhibit good charge transfer and hole transporting properties, which are being explored for a multitude of optoelectronic and photocatalytic applications, including organic light emitting diodes (OLEDs) (Mi et al., 2003). In carbazole derivatives, the preliminary study shows that the presence of oxygenated substituents increases their biological activity (Hewlins, Oliveira-Campos & Shannon, 1984). The 2,3-disubstituted indoles have been used as bidentate synthons for the synthesis of various medicinally important carbazole alkaloids (Mohanakrishnan & Srinivasan, 1995). Intercalation between the base pairs in DNA has been implicated for their anticancer activity. It was conceived that the benzo[b] carbazoles as isosteric analogs of pyrido[4,3-b]carbazoles, with oxygenated D-ring could mimic the anti-cancer activity of ellipticine. So it was of interest to study the anticancer activity of D-ring oxygenated benzo[b]carbazoles as it is believed that these molecules could form a stable intercalation complex with DNA (Kansal & Potier, 1986). Tetrahydrocarbazole derivatives are present in the framework of indole-type alkaloids of biological interest (Phillipson & Zenk, 1980; Saxton, 1983; Abraham, 1975). Here we report the crystal and molecular structure of the title compound, 9-ethyl-1,2,3-trihydrocarbazol-4(2H)-one (Fig. 1).

The planarities of rings A and C are fairly good. The bond lengths C8—O1, N1—C5 and N1—C12 are normal and comparable with the corresponding values observed in the related structure. (Govindasamy et al., 1999). The atom O1 deviates by -0.033 (1) Å from the least-squares plane of the ring C. The cyclohexane ring of the carbazole moiety adopts sofa conformation, with lowest displacement asymmetric parameter (Nardelli, 1983), ΔC_s(C7) = 2.26 (1) °, and puckering parameter (Cremer & Popple, 1975) q2 = 0.373 (2) Å and φ = 359.1 (2) °. The crystal packing (Fig. 2) is stabilized by a C—H···O interaction between a methyl H atom of the ethyl substituent and the oxygen of the carbonyl group of an adjacent molecule, with a C14—H14A···O1ⁱ separation of 2.60 Å (Fig. 2 and Table 1; symmetry code as in Fig. 2). The molecular packing (Fig. 2) is further stabilized by a type-II carbonyl-carbonyl interaction (Allen et al., 1998), with C8···O1ⁱⁱ and O1···C8ⁱⁱ distance of 3.207 (2) Å (symmetry code as in Fig. 2).

Experimental

A mixture of (0.5 g, 1.0 mol), ethyl bromide (0.18 g, 1.0 mol) and potassium carbonate (2.0 g) in 1,4-dioxane (10 ml) was refluxed for ca. 5.0 h. Then the reaction mixture was poured in water and then the crude solid was filtered. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the title compound in ethanol at room temperature.