4,8-Dimethyl­pyrano[2,3-a]carbazol-2(11H)-one

M Sridharan; K J Rajendra Prasad; A Thomas Gunaseelan; A Thiruvalluvar; R J Butcher

doi:10.1107/S1600536809009854

. 2009 Mar 25;65(Pt 4):o830. doi: 10.1107/S1600536809009854

4,8-Dimethylpyrano[2,3-a]carbazol-2(11H)-one

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

PMCID: PMC2968986 PMID: 21582550

Abstract

The molecule of the title compound, C₁₇H₁₃NO₂, is nearly planar, the r.m.s. deviation for all non-H atoms excluding the two methyl C atoms being 0.089 Å. Intermolecular N—H⋯O and C—H⋯O hydrogen bonds are found in the crystal structure. C—H⋯π interactions are also found. The H atoms of the methyl group attached to the benzene ring are disordered equally over two positions.

Related literature

For the synthesis of 2-methyl- and 2-phenyl-pyrano[2,3-a]carbazol-4-ones and their derivatives, see: Kavitha & Rajendra Prasad (2003 ▶). For related crystal structures, see: Sridharan et al. (2007 ▶); Sridharan et al. (2008a ▶,b ▶); Sridharan et al. (2008 ▶).

Experimental

Crystal data

C₁₇H₁₃NO₂
M _r = 263.28
Monoclinic,
a = 26.8502 (4) Å
b = 6.8202 (1) Å
c = 15.8265 (3) Å
β = 115.531 (2)°
V = 2615.21 (9) Å³
Z = 8
Cu Kα radiation
μ = 0.71 mm⁻¹
T = 295 K
0.48 × 0.45 × 0.18 mm

Data collection

Oxford Diffraction Gemini R diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T _min = 0.313, T _max = 1.000 (expected range = 0.276–0.880)
6122 measured reflections
2703 independent reflections
2218 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.132
S = 1.07
2703 reflections
186 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; 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, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809009854/wn2315sup1.cif

e-65-0o830-sup1.cif^{(22.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809009854/wn2315Isup2.hkl

e-65-0o830-Isup2.hkl^{(130.1KB, 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
N11—H11⋯O2ⁱ	0.86 (2)	2.01 (2)	2.814 (2)	154.5 (19)
C14—H14B⋯O2ⁱⁱ	0.96	2.39	3.338 (2)	168
C6—H6⋯Cg1ⁱⁱⁱ	0.93	2.90	3.389 (1)	114
C5—H5⋯Cg2ⁱⁱⁱ	0.93	2.98	3.626 (1)	128

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg1 is the centroid of the pyrrole ring and Cg2 is the centroid of the C6B–C10A ring.

Acknowledgments

We acknowledge the UGC, New Delhi, India, for the award of Major Research Project grant No. F.No.31–122/2005. MS thanks the UGC, New Delhi, India, for the award of a research fellowship. RJB acknowledges the NSF MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer.

supplementary crystallographic information

Comment

The title compound has been analysed as part of our crystallographic studies on pyranocarbazolones. Sridharan et al. (2007, 2008a, 2008b), also Sridharan et al. (2008) have reported the X-ray crystal sructures of related pyranocarbazolone compounds. Recently we reported (Kavitha & Rajendra Prasad, 2003) the synthesis of 2-methyl- and 2-phenyl- pyrano[2,3-a]carbazol-4-ones and their substituted derivatives.

The molecule of the title compound, C₁₇H₁₃NO₂, (Fig.1) is nearly planar; the r.m.s. deviation for all non-H atoms excluding the two methyl C atoms is 0.089 Å. N11—H11···O2(1/2 - x, 5/2 - y, -z) and C14—H14B···O2(x, -1 + y, z) intermolecular hydrogen bonds are found in the crystal structure. Furthermore, a C6—H6···π(1/2 - x, -1/2 + y, 1/2 - z) interaction involving the pyrrole ring (C6A,C6B,C10A,N11,C11A) and a C5—H5···π (1/2 - x, -1/2 + y, 1/2 - z) interaction involving the fused benzene ring (C6B–C10A) are also found.

Experimental

A mixture of 6-methyl-1-hydroxycarbazole (0.199 g, 0.001 mol) and ethyl acetoacetate (0.001 mol) was treated with fused ZnCl₂/POCl₃ (1.5 g / 6 ml) and heated to 373 K for 4 h. The reaction was monitored by TLC. After completion of the reaction, the mixture was poured on to crushed ice; the solid that separated was filtered off, dried and recrystallized from ethanol to obtain the title compound as the sole product in high yield (0.267 g, 82%).