Ethyl 4-(3-hydroxy­phen­yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxyl­ate

P Mookiah; K Rajesh; T Narasimhamurthy; V Vijayakumar; N Srinivasan

doi:10.1107/S1600536809039877

. 2009 Oct 7;65(Pt 11):o2664. doi: 10.1107/S1600536809039877

Ethyl 4-(3-hydroxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

P Mookiah ^a, K Rajesh ^b, T Narasimhamurthy ^c, V Vijayakumar ^d, N Srinivasan ^a,^*

PMCID: PMC2971334 PMID: 21578275

Abstract

In the molecular structure of the title compound, C₂₁H₂₅NO₄, the dihydropyridine ring adopts a flattened boat conformation while the cyclohexenone ring is in an envelope conformation. In the crystal structure, molecules are linked into a two-dimensional network parallel to (10 Inline graphic ) by N—H⋯O and O—H⋯O hydrogen bonds. The network is generated by R ₄ ⁴(30) and R ₄ ⁴(34) graph-set motifs.

Related literature

For general background to oxoquinoline derivatives, see: Baba (1997 ▶); Baba et al. (1997 ▶,1998 ▶); Koga et al. (1980 ▶); Qi et al. (2007 ▶). For a related structure, see: Czaun et al. (2002 ▶); For graph-set motifs, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C₂₁H₂₅NO₄
M _r = 355.42
Monoclinic,
a = 10.8721 (4) Å
b = 16.1255 (7) Å
c = 11.0856 (4) Å
β = 100.682 (2)°
V = 1909.83 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.26 × 0.15 × 0.12 mm

Data collection

Bruker Kappa APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.93, T _max = 0.95
14667 measured reflections
3163 independent reflections
2137 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.115
S = 1.02
3163 reflections
236 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809039877/ci2916sup1.cif

e-65-o2664-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809039877/ci2916Isup2.hkl

e-65-o2664-Isup2.hkl^{(152KB, 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
O8C—H8C⋯O9Bⁱ	0.82	2.05	2.835 (2)	162
N1—H1⋯O6Aⁱⁱ	0.86	2.16	2.970 (2)	157

Open in a new tab

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

supplementary crystallographic information

Comment

Some oxoquinoline derivatives viz. 8-difluoromethoxy-1-ethyl-6-fluoro-1,4-dihydro-7-[4-(2-methoxyphenyl)- 1-πiperazinyl]- 4-oxoquinoline-3-carboxylic acid (K-12), 7-(3,4-dehydro-4-phenyl-1-piperidinyl)-1,4-dihydro-6-fluoro-1-methyl- 8-trifluoromethyl-4-oxoquinoline-3-carboxylic acid (K-37), 8-difluoromethoxy-1,4-dihydro-6-fluoro-7-(3,4-dehydro-4-phenyl- 1-piperidinyl)-1-[4,(1,2,4-triazol-1-yl)methylphenyl]-4-oxoquinoline- 3-carboxylic acid (K-38) act as potent and selective inhibitor of human immunodeficiency virus type I (HIV-1) transcription (Baba, 1997; Baba et al., 1997,1998). Structure-activity relationships of antibacterial oxoquinolone-3-carboxylic acids have been studied (Koga et al., 1980). In view of the signficicant biological activitiy, precise single crystal structure determinations of these derivatives are expcted to provide insights in their design and function. The crystal structure of 1H-2-phenyl-3-hydroxy-4-oxoquinoline-dimethylsulfoxide has already been reported (Czaun et al., 2002). The expression, purification and crystallization of 1H-3-hydroxy-4-oxoquinoline 2,4-dioxygenase are reported elsewhere (Qi et al., 2007).

The dihydropyridine ring of the title molecule (Fig.1) adopts a flattened boat conformation. The cyclohexenone ring is in an envelope conformation with atom C4 at the flap. The 4-methoxyphenyl ring and the planar part of the dihydropyridine ring (C2/C7/C9/C10) are nearly perpendicular to each other, with a dihedral angle of 89.37 (6)°.

In the crystal structure, molecules are linked into a two-dimensional network (Fig.2) parallel to the (101) by N—H···O and O—H···O hydrogen bonds (Table 1). The two-deimensional layer, resembiling a corrugated sheet, contains R₄⁴(30) and R₄⁴(34) graph-set motifs (Etter et al., 1990) as its fundamental repeating units. It is observed that these rings are assembled through centrosymmetrically related pairs of molecules with no direct hydrogen bonding between them.

Experimental

A 50 ml round-bottomed flask was charged with 3-hydroxybenzaldehyde (1.221 g, 10 mmol), 5,5-dimethyl-1,3-cyclohexanedione (1.402 g, 10 mmol), ethyl acetoacetate (1.265 ml, 10 mmol) and ammonium acetate (0.771 g, 10 mmol) followed by ethanol (10 ml). The mixture was stirred at 343 K for 1.5 h and left aside for a day. The solid separated out was filtered and washed with ethanol-diethyl ether mixture (1:4). It was recrystalyzed from 100% chloroform. Light yellow prismatic crystals of the title compound were obtained by slow evaporation of a methonolic solution. Pale yellow crystals with slab morphology were obtained by slow evaporation of a methonol-chloroform solution.