6-Methyl-2,4-diphenyl­quinoline

Xing Huo; Yanfen Xu; Xinyun Li; Xinfu Pan

doi:10.1107/S1600536808015651

. 2008 Jun 7;64(Pt 7):o1187. doi: 10.1107/S1600536808015651

6-Methyl-2,4-diphenylquinoline

Xing Huo ^a, Yanfen Xu ^a, Xinyun Li ^a, Xinfu Pan ^a,^*

PMCID: PMC2961894 PMID: 21202829

Abstract

The molecules of the title compound, C₂₂H₁₇N, are linked by weak interactions, among which the most prominent are C—H⋯π interactions. The dihedral angles between the phenyl rings and the quinoline ring system are 43.3 (3) and 21.4 (3)°. The title product resulted from a three-component reaction of benzaldehyde, 1-ethynylbenzene and p-toluidine via C—H activation of 1-ethynylbenzene catalyzed by CuI in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate.

Related literature

For related literature, see: Allen et al. (1987 ▶); Park & Alper (2005 ▶); Shi et al. (2004 ▶); Skraup (1880 ▶).

Experimental

Crystal data

C₂₂H₁₇N
M _r = 295.37
Orthorhombic,
a = 7.766 (1) Å
b = 9.851 (1) Å
c = 20.756 (2) Å
V = 1588.0 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 294 (2) K
0.41 × 0.35 × 0.30 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.971, T _max = 0.979
8562 measured reflections
1720 independent reflections
1302 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.120
S = 1.04
1720 reflections
210 parameters
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SMART; data reduction: SAINT (Bruker, 1998 ▶); 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/S1600536808015651/fb2095sup1.cif

e-64-o1187-sup1.cif^{(19.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015651/fb2095Isup2.hkl

e-64-o1187-Isup2.hkl^{(84.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg2 and Cg3 are the centroids of the C1–C6 and C14–C19 rings, respectively .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯Cg3ⁱ	0.93	2.75	3.551 (3)	145
C11—H11⋯Cg2ⁱ	0.93	2.92	3.726 (3)	146

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the State Laboratory of Applied Organic Chemistry, Lanzhou University, for funding this study.

supplementary crystallographic information

Comment

Quinolines and their derivatives are very important in medical chemistry because of their extensive occurrence in natural products. Also, quinolines possess a wide spectrum of biological activities. The classic method of quinoline synthesis is Skraup's procedure (Skraup, 1880). The synthesis of the title compound follows a study of transition-metal catalyzed multi-component reactions which is a powerful synthetic tool to access complex structures from simple precursors by a one-pot procedure (Shi et al., 2004; Park & Alper, 2005).

In the title compound, all the bond lengths are normal (Allen et al., 1987). The angle between both phenyl rings in the structure is 34.6 (3) °. The dihedral angle between the phenyl ring C1—C6 and the ring C14—C21/N1 is 43.3 (3) °. The dihedral angle between the C7—C12 phenyl ring and the C14—C21/N1 ring is 21.4 (3) °.

Experimental

The p-toluidine (1.5 mmol) and benzaldehyde(1.5 mmol) were taken along with a catalytic quantity of CuI (0.45 mmol) in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (5 ml) (Scheme 2). The resulting mixture was stirred at 298 K for 15 minutes. At this stage 1-ethynylbenzene (1 mmol) was quickly poured into the reaction mixture and the temperature was raised to 404 K, kept at this temperature for 6 hours, then cooled to room temperature. The product was extracted from the reaction mixture by addition of diethyl ether. (It was possible to recover ionic liquid layer and to use it again without any pretreatment.) The combined organic layer was concentrated and the desired product was isolated by silica gel column chromatography(petrol/EtOAc, 20:1). Colourless sheet crystals were recrystallized from the deuterated chloroform CDCl3 by evaporation in the course of several days. Their average size was 2.5-3 mm.