Dimethyl 5,6,7-trimeth­oxy-2-methyl-1,2-dihydro­quinoline-2,4-dicarboxyl­ate

Zeynep Gültekin; Wolfgang Frey; Tuncer Hökelek

doi:10.1107/S1600536811004028

. 2011 Feb 5;67(Pt 3):o576. doi: 10.1107/S1600536811004028

Dimethyl 5,6,7-trimethoxy-2-methyl-1,2-dihydroquinoline-2,4-dicarboxylate

Zeynep Gültekin ^a, Wolfgang Frey ^b, Tuncer Hökelek ^c,^*

PMCID: PMC3051996 PMID: 21522338

Abstract

In the title compound, C₁₇H₂₁NO₇, the dihydropyridine ring assumes a screw-boat conformation. In the crystal, intermolecular C—H⋯O hydrogen bonds link the molecules, forming supramolecular chains running along the b axis.

Related literature

For the preparation of 1,2-dihydroquinoline, see: Edwards et al. (1998 ▶); Yan et al. (2004 ▶); Petasis & Butkevich (2009 ▶); Johnson et al. (1989 ▶); Gültekin et al. (2010 ▶); Waldmann et al. (2008 ▶). For the biological activity of dihydroquinolines, see: Elmore et al. (2001 ▶); Dillard et al. (1973 ▶); Muren & Weissmann (1971 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₇H₂₁NO₇
M _r = 351.35
Orthorhombic,
a = 10.476 (2) Å
b = 16.552 (4) Å
c = 20.238 (4) Å
V = 3509.2 (13) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 294 K
0.6 × 0.4 × 0.15 mm

Data collection

Nicolet P3 diffractometer
3447 measured reflections
3447 independent reflections
1839 reflections with I > 2σ(I)
3 standard reflections every 50 reflections intensity decay: 1%

Refinement

R[F ² > 2σ(F ²)] = 0.070
wR(F ²) = 0.156
S = 1.07
3447 reflections
237 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811004028/xu5153sup1.cif

e-67-0o576-sup1.cif^{(20.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004028/xu5153Isup2.hkl

e-67-0o576-Isup2.hkl^{(165.7KB, 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
C14—H14A⋯O1ⁱ	0.96	2.51	3.251 (6)	134

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Symmetry code: (i) Inline graphic .

Acknowledgments

This research was carried out at RWTH Aachen University. The authors thank Professor Magnus Rueping of RWTH Aachen University, Germany, for helpful discussions.

supplementary crystallographic information

Comment

Dihydroquinolines have been widely studied and found an important structural unit in synthetic organic and medicinal chemistry (Elmore et al., 2001; Dillard et al., 1973; Muren & Weissmann, 1971). Many dihydroquinoline derivatives have been reported in the literature (Edwards et al., 1998; Yan et al., 2004; Petasis & Butkevich, 2009; Gültekin et al., 2010) and some of them have biological effects. For example, 2,2,4-substituted 1,2-dihydroquinolines have been shown antibacterial activities (Johnson et al., 1989).

In the title compound, (I), (Fig. 1), the ring A (C1-C4/C9/N1) is not planar; the puckering parameters (Cremer & Pople, 1975) Q_T = 0.379 (3) Å, φ = 21.5 (6)° and θ = 66.4 (5)° suggesting a screw-boat conformation. In the crystal structure, intermolecular C-H···O hydrogen bonds (Table 1) link the molecules to form infinite chains along the b-axis (Fig. 2).

Experimental

The title compound was synthesized by the literature method (Waldmann et al., 2008). 3,4,5-dimethoxyaniline (100 mg, 1 eq) was dissolved in chloroform (1.5 ml) in a screw-capped test tube and Bi(OTf)₃ (5 mol%, 0.05 eq) was added to the mixture. The mixture was stirred at room temperature for 4 h until the starting material was completely consumed as monitored by TLC. The resultant residue was directly purified by flash chromatography on silica (EtOAc:Cylohexane 2:98) gave in 83% yield as a yellow solid. Recrystallized over pentane and ethyl acetate (70:30) gave yellow crystalline solid R_f 0.16 (2:1 Cyclohexane/EtOAc) mp 394-395 K.