8-Methyl-4-phenyl-2,3,3a,4,5,9b-hexa­hydro­furo[3,2-c]quinoline

Pingping Lu; Chaomei Lian; Yulin Zhu

doi:10.1107/S1600536809051125

. 2009 Dec 4;66(Pt 1):o17. doi: 10.1107/S1600536809051125

8-Methyl-4-phenyl-2,3,3a,4,5,9b-hexahydrofuro[3,2-c]quinoline

Pingping Lu ^a, Chaomei Lian ^a, Yulin Zhu ^a,^*

PMCID: PMC2980039 PMID: 21580056

Abstract

The title compound, C₁₈H₁₉NO, was synthesized from the multi-component one-pot reaction between p-toluidine, benzaldehyde and 2,3-dihydrofuran in the presence of palladium dichloride. There are two molecules in the asymmetric unit. The crystal packing is stabilized by classical intermolecular N—H⋯O hydrogen bonds.

Related literature

For heterocyclic scaffolds of biologically active alkaloids, see: Johnson et al. (1989 ▶); Yamada et al. (1992 ▶); Katritzky & Rachwal (1996 ▶). For the synthesis of related compounds, see: Buonora et al. (2001 ▶); Syamala (2005 ▶).

Experimental

Crystal data

C₁₈H₁₉NO
M _r = 265.34
Monoclinic,
a = 12.751 (4) Å
b = 17.780 (5) Å
c = 17.516 (4) Å
β = 132.426 (14)°
V = 2931.3 (15) Å³
Z = 8
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 295 K
0.30 × 0.15 × 0.15 mm

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.987, T _max = 0.989
14911 measured reflections
5280 independent reflections
2114 reflections with I > 2σ(I)
R _int = 0.067

Refinement

R[F ² > 2σ(F ²)] = 0.069
wR(F ²) = 0.186
S = 1.17
5280 reflections
315 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809051125/rk2180sup1.cif

e-66-00o17-sup1.cif^{(27.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809051125/rk2180Isup2.hkl

e-66-00o17-Isup2.hkl^{(258.6KB, 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
N1—H1⋯O2	0.86	2.41	2.959 (4)	122
N2—H2⋯O1ⁱ	0.86	2.15	2.934 (4)	151

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank South China Normal University for financial support (grant Nos. SCNU033038 and SCNU524002).

supplementary crystallographic information

Comment

Tetrahydroquinolines are well known as important heterocyclic scaffolds in many biologically active alkaloids, examples including flindersine, oricine and verprisine (Johnson et al., 1989; Katritzky & Rachwal, 1996; Yamada et al., 1992). Aza Diels-Alder reaction which a one-pot condensation of aryl amine, aromatic aldehydes and 2,3-dihydrofuran or 3,4-dihydro-2H-pyran is a wellestablished method used for the construction of tetrahydroquinolines (Buonora et al., 2001; Syamala, 2005). The reaction between p-toluidine, benzaldehyde and 2,3-dihydrofuran in the presence of palladium dichloride proceeded to give the title compound in isolated yield 92.6% (Fig. 1). A representation of the title compound is given in Fig. 2. There are no unusual bond lengths and angles in the compound and the trans- and cis-conformations were both formed in the reaction. The compound contains two different size rings: the tetrahydropyranoquinoline ring connected a phenyl ring, the structure about two rings connected each other via C12–C13 and C30–C31 bonds. In addition, the molecules in the structure are linked via intermolecular hydrogen bonds N1–H1···O2 and N2–H2···O1ⁱ. Symmetry code: (i) -x+1, y-1/2, -z+1/2.

Experimental

A mixture of p-toluidine (1.07 g, 10 mmol), benzaldehyde (1.06 g, 10 mmol), 2,3-dihydrofuran (0.84 g, 12 mmol), and palladium dichloride (0.0020 mg) was refluxed in acetonitrile (12 ml) at 373 K for 10 h. After being cooled to room temperature, the reaction mixture was poured into water. The white precipitate was filtered off with a silica pad, washed twice with water, and the filtrate was then dried under vacuum. Yield 92.6%. Single crystals of the title compound were obtained by slow evaporation from ethanol at room temperature to yield colourless, block-shaped crystal.