6-Meth­oxy-2,3,4,9-tetra­hydro-1H-carbazol-1-one

M Sridharan; K J Rajendra Prasad; A Thomas Gunaseelan; A Thiruvalluvar; A Linden

doi:10.1107/S1600536808007885

. 2008 Mar 29;64(Pt 4):o763–o764. doi: 10.1107/S1600536808007885

6-Methoxy-2,3,4,9-tetrahydro-1H-carbazol-1-one

M Sridharan ^a, K J Rajendra Prasad ^a, A Thomas Gunaseelan ^b, A Thiruvalluvar ^b,^*, A Linden ^c

PMCID: PMC2960955 PMID: 21202152

Abstract

The carbazole unit of the title molecule, C₁₃H₁₃NO₂, is not planar. The dihedral angle between the benzene ring and the pyrrole ring is 1.69 (6)°. The cyclohexene ring adopts an envelope conformation. Intermolecular C—H⋯O and N—H⋯O hydrogen bonds are present in the crystal structure. A C—H⋯π interaction, involving the benzene ring, is also found in the crystal structure.

Related literature

For related literature, see: Bhattacharya & Chakraborty (1987 ▶); Chakraborty & Roy (1991 ▶); Chakraborty (1993 ▶); Knolker (1986 ▶); Lescot et al. (1986 ▶); Hook et al. (1990 ▶); Hirata et al. (1999 ▶); Kapil (1971 ▶); Knolker & Reddy (2002 ▶); Sowmithran & Rajendra Prasad (1986 ▶); Rajendra Prasad & Vijayalakshmi (1994 ▶). Gunaseelan et al. (2007a ▶,b ▶) and Thiruvalluvar et al. (2007 ▶) have reported the crystal structures of substituted carbazole derivatives, in which the carbazole units are not planar.

Experimental

Crystal data

C₁₃H₁₃NO₂
M _r = 215.24
Monoclinic,
a = 9.0627 (2) Å
b = 14.0285 (3) Å
c = 8.5506 (2) Å
β = 101.815 (1)°
V = 1064.06 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 160 (1) K
0.35 × 0.28 × 0.13 mm

Data collection

Nonius KappaCCD area-detector diffractometer
Absorption correction: none
28554 measured reflections
3077 independent reflections
2601 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.145
S = 1.12
3077 reflections
149 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: COLLECT (Nonius, 2000 ▶); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN and SCALEPACK (Otwinowski & Minor, 1997 ▶); 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: PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808007885/wn2245sup1.cif

e-64-0o763-sup1.cif^{(20.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808007885/wn2245Isup2.hkl

e-64-0o763-Isup2.hkl^{(147.9KB, 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
N9—H9⋯O1ⁱ	0.948 (17)	1.918 (17)	2.8313 (14)	161.2 (15)
C2—H2A⋯O2ⁱⁱ	0.99	2.52	3.4962 (15)	169
C4—H4B⋯Cgⁱⁱⁱ	0.99	2.57	3.492 (1)	156

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg is the centroid of the benzene ring.

Acknowledgments

KJR acknowledges the UGC, New Delhi, India, for the award of a Major Research Project grant F.No.31–122/2005. MS thanks the UGC, New Delhi for the award of a research fellowship.

supplementary crystallographic information

Comment

Heterocylic compounds are encountered in a very large number of groups of organic compounds. They play a vital role in the metabolism of all living cells, which are widely distributed in nature and are essential to life. Among them the carbazole heterocycles have emerged as an important class, based on their fascinating structure and high degree of biological activities (Bhattacharya & Chakraborty,1987; Chakraborty & Roy, 1991; Chakraborty, 1993). A number of carbazole alkaloids with intriguing novel structures and useful biological activities were isolated from natural sources over the past decades; these attracted chemists to frame novel synthetic strategies towards the synthesis of carbazole and its derivatives (Knolker,1986; Lescot et al., 1986). These alkaloids represent a new and interesting variant in the large number of indole alkaloids, which have yielded several important drugs. Several reports have appeared on the synthesis of carbazole derivatives, in connection with the search for newer physiologically active compounds (Hook et al., 1990; Hirata et al., 1999; Kapil, 1971; Knolker & Reddy, 2002). The preparation of 1-oxo compounds via their corresponding hydrazones have been reported (Sowmithran & Rajendra Prasad, 1986; Rajendra Prasad & Vijayalakshmi, 1994).

Gunaseelan et al. (2007a,b) and Thiruvalluvar et al. (2007) have reported the crystal structures of substituted carbazole derivatives, in which the carbazole units are not planar. The molecular structure of the title compound, with atomic numbering scheme, is shown in Fig. 1. The carbazole unit of the title molecule is not planar. The dihedral angle between the benzene ring and the pyrrole ring is 1.69 (6)°. The cyclohexene ring adopts an envelope conformation. Intermolecular C2—H2A···O2(x + 1, y, z + 1) and N9—H9···O1(-x + 1, -y + 1, -z + 1) hydrogen bonds are present in the crystal structure (Fig. 2). A C4—H4B···π(x, 3/2 - y,1/2 + z) interaction involving the benzene ring is also found in the structure, .

Experimental

A solution of 2-(2-(4-methoxyphenyl)hydrazono)cyclohexanone (232 mg, 0.001 mol) in a mixture of acetic acid (20 ml) and hydrochloric acid (5 ml) was refluxed on an oil bath pre-heated to 398-403 K for 2 h. The reaction was monitored by TLC. After completion of the reaction the contents were cooled and poured on to cold water with stirring. The brown solid which separated was purified by passing through a column of silica gel and eluting with a (95:5) petroleum ether-ethyl acetate mixture, yielding the title compound (144 mg, 67%). The compound thus obtained was recrystallized using ethanol.