
Acta Cryst. (2008). E64, o763-o764 [ doi:10.1107/S1600536808007885 ]
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
interaction, involving the benzene ring, is also found in the crystal structure.
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.
The H atom bonded to N9 was located in a difference Fourier map and refined isotropically. Other H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95–0.99 Å and Uiso(H) = xUeq(parent atom), where x = 1.5 for methyl and 1.2 for all other carbon-bound H atoms.
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).
| C13H13NO2 | F000 = 456 |
| Mr = 215.24 | Dx = 1.344 Mg m−3 |
| Monoclinic, P21/c | Melting point: 536 K |
| Hall symbol: -P 2ybc | Mo Kα radiation λ = 0.71073 Å |
| a = 9.0627 (2) Å | Cell parameters from 3175 reflections |
| b = 14.0285 (3) Å | θ = 2.0–30.0º |
| c = 8.5506 (2) Å | µ = 0.09 mm−1 |
| β = 101.815 (1)º | T = 160 (1) K |
| V = 1064.06 (4) Å3 | Tablet, colourless |
| Z = 4 | 0.35 × 0.28 × 0.13 mm |
| Nonius KappaCCD area-detector diffractometer | 3077 independent reflections |
| Radiation source: Nonius FR590 sealed tube generator | 2601 reflections with I > 2σ(I) |
| Monochromator: horizontally mounted graphite crystal | Rint = 0.038 |
| Detector resolution: 9 pixels mm-1 | θmax = 30.0º |
| T = 160(1) K | θmin = 2.3º |
| φ and ω scans with κ offsets | h = −12→12 |
| Absorption correction: none | k = 0→19 |
| 28554 measured reflections | l = 0→12 |
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.043 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.146 | w = 1/[σ2(Fo2) + (0.0825P)2 + 0.2332P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.12 | (Δ/σ)max < 0.001 |
| 3077 reflections | Δρmax = 0.33 e Å−3 |
| 149 parameters | Δρmin = −0.24 e Å−3 |
| Primary atom site location: structure-invariant direct methods | Extinction correction: none |
| C13H13NO2 | V = 1064.06 (4) Å3 |
| Mr = 215.24 | Z = 4 |
| Monoclinic, P21/c | Mo Kα |
| a = 9.0627 (2) Å | µ = 0.09 mm−1 |
| b = 14.0285 (3) Å | T = 160 (1) K |
| c = 8.5506 (2) Å | 0.35 × 0.28 × 0.13 mm |
| β = 101.815 (1)º |
| Nonius KappaCCD area-detector diffractometer | 3077 independent reflections |
| Absorption correction: none | 2601 reflections with I > 2σ(I) |
| 28554 measured reflections | Rint = 0.038 |
| R[F2 > 2σ(F2)] = 0.043 | 149 parameters |
| wR(F2) = 0.146 | H atoms treated by a mixture of independent and constrained refinement |
| S = 1.12 | Δρmax = 0.33 e Å−3 |
| 3077 reflections | Δρmin = −0.24 e Å−3 |
Experimental. Solvent used: EtOH Cooling Device: Oxford Cryosystems Cryostream 700 Crystal mount: glued on a glass fibre Mosaicity (°.): 0.742 (2) Frames collected: 359 Seconds exposure per frame: 100 Degrees rotation per frame: 2.0 Crystal-Detector distance (mm): 30.0 |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.53223 (10) | 0.52978 (7) | 0.72771 (11) | 0.0324 (3) | |
| O2 | −0.29638 (10) | 0.67151 (8) | 0.18475 (11) | 0.0354 (3) | |
| N9 | 0.27900 (11) | 0.55709 (7) | 0.45710 (11) | 0.0229 (3) | |
| C1 | 0.41200 (13) | 0.56555 (8) | 0.74513 (13) | 0.0229 (3) | |
| C2 | 0.38660 (13) | 0.59515 (9) | 0.90781 (13) | 0.0251 (3) | |
| C3 | 0.27324 (13) | 0.67715 (8) | 0.90149 (13) | 0.0236 (3) | |
| C4 | 0.12214 (12) | 0.65469 (8) | 0.79020 (12) | 0.0213 (3) | |
| C4A | 0.14868 (12) | 0.61976 (7) | 0.63321 (12) | 0.0196 (3) | |
| C4B | 0.05307 (12) | 0.61980 (7) | 0.47874 (13) | 0.0197 (3) | |
| C5 | −0.09638 (12) | 0.65107 (8) | 0.42156 (13) | 0.0219 (3) | |
| C6 | −0.15394 (12) | 0.64344 (8) | 0.25953 (13) | 0.0241 (3) | |
| C7 | −0.06690 (13) | 0.60611 (8) | 0.15394 (13) | 0.0253 (3) | |
| C8 | 0.07867 (13) | 0.57456 (8) | 0.20802 (13) | 0.0236 (3) | |
| C8A | 0.13856 (12) | 0.58090 (7) | 0.37241 (13) | 0.0208 (3) | |
| C9A | 0.28448 (12) | 0.58046 (8) | 0.61527 (13) | 0.0213 (3) | |
| C16 | −0.38951 (15) | 0.71146 (13) | 0.28342 (18) | 0.0441 (5) | |
| H2A | 0.48420 | 0.61484 | 0.97491 | 0.0301* | |
| H2B | 0.34978 | 0.53939 | 0.95963 | 0.0301* | |
| H3A | 0.25628 | 0.68946 | 1.01044 | 0.0283* | |
| H3B | 0.31607 | 0.73572 | 0.86390 | 0.0283* | |
| H4A | 0.06803 | 0.60539 | 0.83938 | 0.0256* | |
| H4B | 0.05882 | 0.71278 | 0.77373 | 0.0256* | |
| H5 | −0.15509 | 0.67641 | 0.49192 | 0.0262* | |
| H7 | −0.10988 | 0.60272 | 0.04300 | 0.0303* | |
| H8 | 0.13633 | 0.54942 | 0.13648 | 0.0284* | |
| H9 | 0.3587 (19) | 0.5296 (12) | 0.416 (2) | 0.038 (4)* | |
| H16A | −0.48742 | 0.72886 | 0.21742 | 0.0661* | |
| H16B | −0.34089 | 0.76845 | 0.33697 | 0.0661* | |
| H16C | −0.40428 | 0.66454 | 0.36374 | 0.0661* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0269 (5) | 0.0436 (5) | 0.0274 (4) | 0.0137 (4) | 0.0075 (3) | −0.0016 (4) |
| O2 | 0.0230 (4) | 0.0513 (6) | 0.0293 (5) | 0.0061 (4) | −0.0008 (3) | −0.0103 (4) |
| N9 | 0.0239 (5) | 0.0262 (5) | 0.0202 (4) | 0.0049 (3) | 0.0084 (3) | −0.0009 (3) |
| C1 | 0.0245 (5) | 0.0232 (5) | 0.0222 (5) | 0.0045 (4) | 0.0076 (4) | 0.0004 (4) |
| C2 | 0.0249 (5) | 0.0302 (6) | 0.0205 (5) | 0.0067 (4) | 0.0054 (4) | −0.0010 (4) |
| C3 | 0.0235 (5) | 0.0252 (5) | 0.0227 (5) | 0.0028 (4) | 0.0064 (4) | −0.0045 (4) |
| C4 | 0.0224 (5) | 0.0233 (5) | 0.0196 (5) | 0.0030 (4) | 0.0073 (4) | −0.0010 (4) |
| C4A | 0.0215 (5) | 0.0188 (5) | 0.0199 (5) | 0.0012 (3) | 0.0073 (4) | 0.0012 (3) |
| C4B | 0.0215 (5) | 0.0182 (5) | 0.0205 (5) | −0.0004 (4) | 0.0071 (4) | −0.0004 (3) |
| C5 | 0.0212 (5) | 0.0223 (5) | 0.0232 (5) | −0.0014 (4) | 0.0071 (4) | −0.0022 (4) |
| C6 | 0.0208 (5) | 0.0260 (5) | 0.0249 (5) | −0.0018 (4) | 0.0036 (4) | −0.0033 (4) |
| C7 | 0.0274 (6) | 0.0272 (5) | 0.0211 (5) | −0.0025 (4) | 0.0045 (4) | −0.0034 (4) |
| C8 | 0.0276 (5) | 0.0245 (5) | 0.0204 (5) | −0.0009 (4) | 0.0089 (4) | −0.0025 (4) |
| C8A | 0.0231 (5) | 0.0200 (5) | 0.0210 (5) | 0.0001 (4) | 0.0085 (4) | −0.0005 (3) |
| C9A | 0.0232 (5) | 0.0222 (5) | 0.0197 (5) | 0.0030 (4) | 0.0073 (4) | 0.0002 (4) |
| C16 | 0.0261 (6) | 0.0610 (10) | 0.0421 (8) | 0.0118 (6) | 0.0000 (5) | −0.0185 (7) |
| O1—C1 | 1.2360 (15) | C6—C7 | 1.4154 (16) |
| O2—C6 | 1.3756 (15) | C7—C8 | 1.3785 (17) |
| O2—C16 | 1.4247 (18) | C8—C8A | 1.4021 (15) |
| N9—C8A | 1.3706 (15) | C2—H2A | 0.9900 |
| N9—C9A | 1.3826 (14) | C2—H2B | 0.9900 |
| N9—H9 | 0.948 (17) | C3—H3A | 0.9900 |
| C1—C9A | 1.4446 (16) | C3—H3B | 0.9900 |
| C1—C2 | 1.5138 (16) | C4—H4A | 0.9900 |
| C2—C3 | 1.5359 (17) | C4—H4B | 0.9900 |
| C3—C4 | 1.5318 (16) | C5—H5 | 0.9500 |
| C4—C4A | 1.4940 (14) | C7—H7 | 0.9500 |
| C4A—C4B | 1.4236 (15) | C8—H8 | 0.9500 |
| C4A—C9A | 1.3854 (16) | C16—H16A | 0.9800 |
| C4B—C8A | 1.4189 (15) | C16—H16B | 0.9800 |
| C4B—C5 | 1.4124 (16) | C16—H16C | 0.9800 |
| C5—C6 | 1.3810 (15) | ||
| O1···N9 | 2.9314 (13) | C16···H3Bviii | 2.9800 |
| O1···N9i | 2.8313 (14) | H2A···O2x | 2.5200 |
| O1···H9 | 2.804 (17) | H2A···C16x | 2.9800 |
| O1···H2Bii | 2.8400 | H2A···H16Ax | 2.5900 |
| O1···H9i | 1.918 (17) | H2B···O1ii | 2.8400 |
| O2···H2Aiii | 2.5200 | H2B···C2ii | 3.0700 |
| N9···O1 | 2.9314 (13) | H3A···C8xi | 3.0300 |
| N9···O1i | 2.8313 (14) | H3A···H8xi | 2.5900 |
| C1···C16iv | 3.590 (2) | H3B···C9A | 3.0200 |
| C2···C2ii | 3.5370 (17) | H3B···C8Av | 3.0400 |
| C3···C8Av | 3.5983 (15) | H3B···C16iv | 2.9800 |
| C4B···C4Bvi | 3.5353 (14) | H3B···H16Aiv | 2.4300 |
| C6···C9Avi | 3.5958 (16) | H4A···C7vi | 2.9700 |
| C8A···C3vii | 3.5983 (15) | H4A···C8vi | 2.8400 |
| C9A···C6vi | 3.5958 (16) | H4B···C4Bv | 2.9400 |
| C16···C1viii | 3.590 (2) | H4B···C5v | 2.8200 |
| C1···H16Aiv | 3.0500 | H4B···C6v | 2.7800 |
| C1···H9i | 3.028 (17) | H4B···C7v | 2.8900 |
| C2···H2Bii | 3.0700 | H4B···C8v | 3.0500 |
| C4B···H4Bvii | 2.9400 | H4B···C8Av | 3.0600 |
| C5···H16C | 2.7400 | H5···C16 | 2.5300 |
| C5···H4Bvii | 2.8200 | H5···H16B | 2.3100 |
| C5···H16B | 2.7400 | H5···H16C | 2.3100 |
| C6···H4Bvii | 2.7800 | H8···H3Aix | 2.5900 |
| C7···H4Bvii | 2.8900 | H9···O1 | 2.804 (17) |
| C7···H4Avi | 2.9700 | H9···O1i | 1.918 (17) |
| C8···H4Bvii | 3.0500 | H9···C1i | 3.028 (17) |
| C8···H4Avi | 2.8400 | H16A···H2Aiii | 2.5900 |
| C8···H3Aix | 3.0300 | H16A···C1viii | 3.0500 |
| C8A···H4Bvii | 3.0600 | H16A···H3Bviii | 2.4300 |
| C8A···H3Bvii | 3.0400 | H16B···C5 | 2.7400 |
| C9A···H3B | 3.0200 | H16B···H5 | 2.3100 |
| C16···H2Aiii | 2.9800 | H16C···C5 | 2.7400 |
| C16···H5 | 2.5300 | H16C···H5 | 2.3100 |
| C6—O2—C16 | 116.79 (10) | C1—C2—H2A | 109.00 |
| C8A—N9—C9A | 107.61 (9) | C1—C2—H2B | 109.00 |
| C9A—N9—H9 | 125.6 (10) | C3—C2—H2A | 109.00 |
| C8A—N9—H9 | 126.8 (10) | C3—C2—H2B | 109.00 |
| O1—C1—C9A | 123.53 (10) | H2A—C2—H2B | 108.00 |
| O1—C1—C2 | 121.72 (10) | C2—C3—H3A | 109.00 |
| C2—C1—C9A | 114.73 (10) | C2—C3—H3B | 109.00 |
| C1—C2—C3 | 113.55 (9) | C4—C3—H3A | 109.00 |
| C2—C3—C4 | 111.98 (9) | C4—C3—H3B | 109.00 |
| C3—C4—C4A | 109.74 (9) | H3A—C3—H3B | 108.00 |
| C4B—C4A—C9A | 106.45 (9) | C3—C4—H4A | 110.00 |
| C4—C4A—C4B | 130.85 (10) | C3—C4—H4B | 110.00 |
| C4—C4A—C9A | 122.69 (10) | C4A—C4—H4A | 110.00 |
| C5—C4B—C8A | 120.56 (10) | C4A—C4—H4B | 110.00 |
| C4A—C4B—C8A | 106.61 (9) | H4A—C4—H4B | 108.00 |
| C4A—C4B—C5 | 132.82 (10) | C4B—C5—H5 | 121.00 |
| C4B—C5—C6 | 117.50 (10) | C6—C5—H5 | 121.00 |
| O2—C6—C5 | 124.74 (10) | C6—C7—H7 | 119.00 |
| O2—C6—C7 | 113.70 (10) | C8—C7—H7 | 119.00 |
| C5—C6—C7 | 121.55 (10) | C7—C8—H8 | 121.00 |
| C6—C7—C8 | 121.66 (10) | C8A—C8—H8 | 121.00 |
| C7—C8—C8A | 117.60 (10) | O2—C16—H16A | 109.00 |
| N9—C8A—C8 | 129.88 (10) | O2—C16—H16B | 109.00 |
| C4B—C8A—C8 | 121.11 (10) | O2—C16—H16C | 109.00 |
| N9—C8A—C4B | 108.97 (9) | H16A—C16—H16B | 109.00 |
| C1—C9A—C4A | 124.16 (10) | H16A—C16—H16C | 109.00 |
| N9—C9A—C1 | 125.48 (10) | H16B—C16—H16C | 109.00 |
| N9—C9A—C4A | 110.36 (10) | ||
| C16—O2—C6—C5 | 0.21 (18) | C4B—C4A—C9A—N9 | 0.74 (12) |
| C16—O2—C6—C7 | −178.89 (12) | C9A—C4A—C4B—C8A | −0.84 (11) |
| C9A—N9—C8A—C8 | 177.52 (11) | C4—C4A—C9A—N9 | −178.17 (10) |
| C8A—N9—C9A—C4A | −0.35 (12) | C4—C4A—C4B—C8A | 177.95 (10) |
| C9A—N9—C8A—C4B | −0.20 (12) | C9A—C4A—C4B—C5 | −179.48 (11) |
| C8A—N9—C9A—C1 | 179.00 (10) | C5—C4B—C8A—N9 | 179.49 (10) |
| C9A—C1—C2—C3 | −29.21 (14) | C4A—C4B—C8A—N9 | 0.65 (12) |
| O1—C1—C2—C3 | 152.17 (11) | C5—C4B—C8A—C8 | 1.54 (16) |
| C2—C1—C9A—N9 | −178.39 (11) | C4A—C4B—C5—C6 | 177.60 (11) |
| C2—C1—C9A—C4A | 0.87 (16) | C8A—C4B—C5—C6 | −0.89 (16) |
| O1—C1—C9A—C4A | 179.47 (11) | C4A—C4B—C8A—C8 | −177.31 (10) |
| O1—C1—C9A—N9 | 0.21 (19) | C4B—C5—C6—O2 | −179.27 (11) |
| C1—C2—C3—C4 | 54.63 (13) | C4B—C5—C6—C7 | −0.24 (16) |
| C2—C3—C4—C4A | −49.23 (12) | O2—C6—C7—C8 | 179.92 (11) |
| C3—C4—C4A—C4B | −156.37 (11) | C5—C6—C7—C8 | 0.80 (18) |
| C3—C4—C4A—C9A | 22.25 (14) | C6—C7—C8—C8A | −0.17 (17) |
| C4—C4A—C4B—C5 | −0.7 (2) | C7—C8—C8A—N9 | −178.45 (11) |
| C4B—C4A—C9A—C1 | −178.62 (10) | C7—C8—C8A—C4B | −0.97 (16) |
| C4—C4A—C9A—C1 | 2.47 (17) |
| Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z+2; (iii) x−1, y, z−1; (iv) x+1, −y+3/2, z+1/2; (v) x, −y+3/2, z+1/2; (vi) −x, −y+1, −z+1; (vii) x, −y+3/2, z−1/2; (viii) x−1, −y+3/2, z−1/2; (ix) x, y, z−1; (x) x+1, y, z+1; (xi) x, y, z+1. |
| 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···O2x | 0.99 | 2.52 | 3.4962 (15) | 169 |
| C4—H4B···Cgv | 0.99 | 2.57 | 3.492 (1) | 156 |
| Symmetry codes: (i) −x+1, −y+1, −z+1; (x) x+1, y, z+1; (v) x, −y+3/2, z+1/2. |
| 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 |
| Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z+1; (iii) x, −y+3/2, z+1/2. |
KJR acknowledges the UGC, New Delhi, India, for the award of a Major Research Project (grant No. F.No.31–122/2005). MS thanks the UGC, New Delhi for the award of a research fellowship.
Bhattacharya, P. & Chakraborty, D. P. (1987). Progress Chem. Org. Nat. Prod., Vol. 52, edited by W. Herz, H. Grisebach, G. W. Kirby & C. Tamm, pp. 299–371. Wien: Springer Verlag. Give title in full
Chakraborty, D. P. (1993). The Alkaloids, Vol. 44, edited by A. Brossi, pp. 257–282. New York: Academic Press.
Chakraborty, D. P. & Roy, S. (1991). Progr. Chem. Org. Nat. Prod. Vol. 57, edited by W. Herz, H. Grisebach, G. W. Kirby & C. Tamm, pp. 71–110. Wien: Springer Verlag. Give title in full
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Gunaseelan, A. T., Thiruvalluvar, A., Martin, A. E. & Prasad, K. J. R. (2007a). Acta Cryst. E63, o2413–o2414.
Gunaseelan, A. T., Thiruvalluvar, A., Martin, A. E. & Prasad, K. J. R. (2007b). Acta Cryst. E63, o2729–o2730.
Hirata, K., Ito, C., Furukawa, H., Itoigawa, M., Cosentino, L. M. & Lee, K. H. (1999). Bioorg. Med. Chem. Lett. 9, 119–122.
Hook, D. J., Yacobucci, J. J., O'Connor, S., Lee, M., Kerns, E., Krishnan, B., Matson, J. & Hesler, G. J. (1990). Antibiot. 43, 1347–1348.
Kapil, R. S. (1971). The Alkaloids, Vol. 13, edited by R. H. F. Manske, p. 273. New York: Academic Press.
Knolker, H. J. (1986). Adv. Nitrogen Heterocycles, Vol. 1, edited by C. J. Moody, p. 273. Geenwich, Connecticut: JAI Press. Give title in full
Knolker, H. J. & Reddy, K. R. (2002). Chem. Rev. 102, 4303–4427.
Lescot, E., Muzard, G., Markovits, J., Belleney, J., Roques, B. P. & Le Pecq, J. B. (1986). J. Med. Chem. 29, 1731–1737.
Nonius (2000). COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C.W. Carter & R.M. Sweet, pp. 307–326. London: Academic Press.
Rajendra Prasad, K. J. & Vijayalakshmi, C. S. (1994). Indian J. Chem. 33B, 481–482.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Sowmithran, D. & Rajendra Prasad, K. J. (1986). Heterocycles, 24, 711–717.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.
Thiruvalluvar, A., Gunaseelan, A. T., Martin, A. E., Prasad, K. J. R. & Butcher, R. J. (2007). Acta Cryst. E63, o3524.
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, .