3-Ethyl-4-hy­droxy-8-meth­oxy­quinolin-2(1H)-one

Stanislav Kafka; Andrej Pevec; Karel Proisl; Roman Kimmel; Janez Košmrlj

doi:10.1107/S1600536812043279

. 2012 Oct 24;68(Pt 11):o3198. doi: 10.1107/S1600536812043279

3-Ethyl-4-hydroxy-8-methoxyquinolin-2(1H)-one

Stanislav Kafka ^a, Andrej Pevec ^b,^*, Karel Proisl ^a, Roman Kimmel ^a, Janez Košmrlj ^b

PMCID: PMC3515288 PMID: 23284508

Abstract

In the title compound, C₁₂H₁₃NO₃, the quinoline ring system is approximately planar with a maximum deviation from the least-squares plane of 0.058 (2) Å. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the molecules into chains running along the b-axis direction. The chains also feature π–π interactions between pyridine and benzene rings of inversion-related molecules [centroid–centroid distance = 3.609 (2) Å].

Related literature

For naturally occurring 3-alkyl-4-hydroxyquinolin-2-ones, see: Paul & Bose (1968 ▶); Faizutdinova et al. (1969 ▶); Jurd et al. (1983 ▶); Chen et al. (1994 ▶); Yamamoto & Harimaya (2004 ▶); Jain et al. (2006 ▶). For the first published synthesis of the title compound, see: Rapoport & Holden (1959 ▶). For recent synthetic utilization of 3-alkyl-4-hydroxyquinolin-2-ones, see, for example: Kimmel et al. (2010 ▶).

Experimental

Crystal data

C₁₂H₁₃NO₃
M _r = 219.23
Monoclinic,
a = 11.4824 (4) Å
b = 6.9072 (2) Å
c = 14.4978 (5) Å
β = 113.1283 (15)°
V = 1057.42 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.35 × 0.25 × 0.08 mm

Data collection

Nonius KappaCCD area-detector diffractometer
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997 ▶) T _min = 0.966, T _max = 0.992
4558 measured reflections
2403 independent reflections
1734 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.077
wR(F ²) = 0.272
S = 1.14
2403 reflections
151 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶) and DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Click here for additional data file.^{(21.7KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812043279/tk5161sup1.cif

e-68-o3198-sup1.cif^{(21.7KB, cif)}

Click here for additional data file.^{(115.7KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812043279/tk5161Isup2.hkl

e-68-o3198-Isup2.hkl^{(115.7KB, hkl)}

Click here for additional data file.^{(4.5KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812043279/tk5161Isup3.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
N1—H1N⋯O1ⁱ	0.85 (2)	2.27 (3)	2.976 (4)	140 (3)
O2—H2⋯O1ⁱⁱ	0.82	1.94	2.665 (4)	147

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

Acknowledgments

This study was supported by the internal grant of TBU in Zlin (No. IGA/FT/2012/043), funded from the resources of specific university research, and the Slovenian Research Agency (Project P1–0230–0103 and Joint Project BI—CZ/07–08–018). This work was also partly supported through the infrastructure of the EN–FIST Centre of Excellence, Ljubljana.

supplementary crystallographic information

Comment

The title compound, (I) (Fig. 1), was recently prepared as an intermediate within the framework of a study focusing on glucosylation of N-unsubstituted 4-hydroxyquinolin-2(1H)-ones by thermal condensation of diethyl ethylmalonate with o-anisidine (Kimmel et al., 2010). Some 3-alkyl-4-hydroxyquinolin-2-ones were isolated from plants Ravenia spectabilis (Paul & Bose, 1968), Haplophylum bucharicum (Faizutdinova et al., 1969), Euxylophora pareansis (Jurd et al., 1983), Zanthoxylum simulans (Chen et al., 1994), Toddalia aculeata (Jain et al., 2006) as well as from the fermentation broth of Dactylosporangium sp. (Yamamoto & Harimaya, 2004).

In the crystal structure of the title compound (I) (Fig. 2) two 3-ethyl-4-hydroxy-8-methoxyquinolin-2(1H)-one molecules are connected by two intermolecular N—H···O hydrogen bonds between protonated nitrogen atom and carbonyl group. These connections altogether with additional O—H···O hydrogen bonds between hydroxyl and carbonyl groups (Table 1) form linear chain along b axis. The chains are further stabilized by π–π interactions between pyridine and benzene rings of inversion-related pairs of quinoline molecules [centroid–centroid distance = 3.609 (2) Å].

Experimental

A mixture of o-anisidine (12.3 g, 100 mmol) and diethyl ethylmalonate (197.6 g, 105 mmol) was heated on a metal bath at 220–230 °C for 1 h and then at 260–270 °C for 6 h (until the distillation of ethanol stopped). The hot reaction mixture was cautiously poured into toluene (50 ml). After cooling, the precipitate was filtered. The residue was dissolved in aqueous sodium hydroxide solution (0.5 M, 300 ml) and the solution was filtered. The filtrate was washed with toluene (3 x 15 ml). The aqueous phase was filtered and acidified by addition of 10% hydrochloric acid to Congo red. The precipitated paste was triturated with a glass bar under an aqueous phase for several minutes and then the mixture was cooled in refrigerator for several hours, until the pasty substance hardened. The solid was filtered off, washed with water (100 ml), air dried and crystallized from ethanol affording 13.6 g (62% of theoretical yield) of the title compound (I), m. pt 496–498 K (benzene – ethanol). In the literature (Rapoport & Holden, 1959), a m. pt range of 498–499 K is reported.