Ethyl 3-benzoyl­indolizine-1-carboxyl­ate

Wei-Jin Gu; Jin Zhuang; Yu-Liang Jiang; Bing-Xiang Wang

doi:10.1107/S160053681104284X

. 2011 Oct 29;67(Pt 11):o3033. doi: 10.1107/S160053681104284X

Ethyl 3-benzoylindolizine-1-carboxylate

Wei-Jin Gu ^a, Jin Zhuang ^a, Yu-Liang Jiang ^a, Bing-Xiang Wang ^a,^*

PMCID: PMC3247427 PMID: 22220045

Abstract

The title compound, C₁₈H₁₅NO₃, consists of an indolizine ring system and an aromatic ring. The two ring systems are not coplanar, the dihedral angle between the two being 54.26 (7)°. In the crystal, inversion dimers are formed by weak C—H⋯O interactions. These dimeric groups are further extended to form a regular two-dimensional structure by additional weak C—H⋯O interactions.

Related literature

For background information on indolizine and its derivatives, see: Tukulula et al. (2010 ▶); James et al. (2008 ▶); Teklu et al. (2005 ▶); Shen et al. (2008 ▶, 2006 ▶). For the synthesis of the title compound, see: Wang et al. (2000 ▶).

Experimental

Crystal data

C₁₈H₁₅NO₃
M _r = 293.31
Monoclinic,
a = 10.030 (2) Å
b = 19.223 (3) Å
c = 7.9652 (17) Å
β = 103.073 (3)°
V = 1495.9 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 291 K
0.24 × 0.20 × 0.18 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.979, T _max = 0.984
8910 measured reflections
2604 independent reflections
1604 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.129
S = 1.00
2604 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681104284X/im2326sup1.cif

e-67-o3033-sup1.cif^{(20KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681104284X/im2326Isup2.hkl

e-67-o3033-Isup2.hkl^{(127.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681104284X/im2326Isup3.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
C1—H1⋯O1ⁱ	0.93	2.45	3.163 (3)	134
C14—H14⋯O3ⁱⁱ	0.93	2.58	3.455 (3)	157

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

We thank the Natural Science Foundation of Jiangsu Province of China (grant No. BK2008435) and the Priority Academic Program Development of Jiangsu Higher Education Institutions for financial support.

supplementary crystallographic information

Comment

Indolizine and it's derivatives have been comprehensively applied in biology and medicine due to their particular structures (Tukulula et al., 2010; James et al., 2008; Teklu et al., 2005). They can also be used as organic fluorescence probes (Shen et al., 2008; Shen et al., 2006). In our continuing studies in organic fluorescence probes, we synthesized the ethyl-3-benzoylindolizine-1-carboxylate (I).

The crystal structure of the title compound, C₁₈H₁₅NO₃, reveals that all bond lengths and angles have normal values (Table 1 and 2). In the asymmetric unit there is one title compound molecule. The molecular structure consists of one indolizine ring A (C1—C8/N) and an aromatic ring B(C10—C15) (Fig. 1). Rings A and ring B are not coplanar with the dihedral angle between them being 54.26 (7) °.

In the crystal packing there are weak C1—H1···O1ⁱ (i: 1 - x,-y,2 - z) interactions between neighbouring molecules forming dimeric groups (Fig. 2). These dimeric groups are further extended into a tegular 2-D structure via weak C14—H14···O3ⁱⁱ (ii: -x,-1/2 + y,0.5 - z) interactions (Fig. 2).

Experimental

Ethyl-3-benzoylindolizine-1-carboxylate was prepared by 1,3-dipolar cycloaddition according to a procedure described in the literature (Wang, et al., 2000). A suspension of N-(benzoylmethyl)pyridinium bromide (C₅H₅N⁺–CH₂COC₆H₅ Br^-) (10 mmol), ethyl acrylate (40 mmol), Et₃N (20 ml) and CrO₃(20 mmol) in DMF (40 ml) was stirred at 90°C for 2 h (monitored by TLC). The mixture was then cooled to room temperature and poured into 5% aqueous HCl (200 mL). The mixture was extracted with CH₂Cl₂ (2 times 50 mL) and the combined extracts were washed with water (2 times 50 mL) and dried over Na₂SO₄. The solvent was removed to give a solid, which was purified by chromatography [silica gel, 20% ethyl acetate in light petroleum (b.p. 60–90°C)] to yield 1.90 g (68%) (I). Yellow crystals were obtained by recrystallization from ethyl acetate at room temperature.

H-NMR (CDCl₃, 400 MHz) δ: 1.41 (t, 3H, CH₃), 4.38 (q, 2H, CH₂), 7.10 (t, 1H, H6), 7.44–7.84 (m, 7H, H7, H2 and PhH), 8.39 (d, 1H, H8), 9.98 (d, 1H, H5).