4-Oxo-1,4-dihydro­benzo[h][1,3]thia­zeto[3,2-a]quinoline-1,3-dicarb­oxy­lic acid

Louise N Dawe; Abeer Ahmed; Mohsen Daneshtalab

doi:10.1107/S1600536811003333

. 2011 Jan 29;67(Pt 2):o529. doi: 10.1107/S1600536811003333

4-Oxo-1,4-dihydrobenzo[h][1,3]thiazeto[3,2-a]quinoline-1,3-dicarboxylic acid

Louise N Dawe ^a, Abeer Ahmed ^b, Mohsen Daneshtalab ^b,^*

PMCID: PMC3051750 PMID: 21523177

Abstract

In the title molecule, C₁₆H₉NO₅S, there is an intramolecular O—H⋯O hydrogen bond involving the quinolone carbonyl O atom and a carboxyl OH group. In the crystal, intermolecular O—H⋯O hydrogen bonds between the carbonyl group of the quinolone carboxyl group, and a second carboxyl group on the thiazeto moiety lead to the formation of chains propagating along [201] and perpendicular to the π-stacks of molecules.

Related literature

For background to the biological importance of thiazetoquinoline antibiotics, see: Ozaki et al. (1991 ▶). For similar work using different procedures, see: Ito et al. (1992 ▶, 1994 ▶); Matsuoka et al. (1999 ▶).

Experimental

Crystal data

C₁₆H₉NO₅S
M _r = 327.31
Monoclinic,
a = 7.237 (2) Å
b = 16.171 (5) Å
c = 11.929 (4) Å
β = 106.081 (8)°
V = 1341.5 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.27 mm⁻¹
T = 153 K
0.18 × 0.04 × 0.04 mm

Data collection

Rigaku Saturn diffractometer
Absorption correction: numerical (ABSCOR; Higashi, 1999 ▶) T _min = 0.974, T _max = 0.996
17300 measured reflections
2769 independent reflections
2614 reflections with I > 2σ(I)
R _int = 0.074

Refinement

R[F ² > 2σ(F ²)] = 0.088
wR(F ²) = 0.164
S = 1.30
2769 reflections
214 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811003333/su2249sup1.cif

e-67-0o529-sup1.cif^{(16.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811003333/su2249Isup2.hkl

e-67-0o529-Isup2.hkl^{(136KB, 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
O5—H5A⋯O1	0.96 (4)	1.57 (4)	2.504 (4)	161 (4)
O3—H3⋯O4ⁱ	0.97 (3)	1.62 (3)	2.569 (4)	166 (3)

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Symmetry code: (i) Inline graphic .

Table 2. π⋯π interactions (Å, °).

Angle of elevation defined as the angle of the Cg(I)→Cg(J) vector and the normal to plane J. Cg1, Cg2 and Cg3 are the centroids of the C7–C12, N1/C1–C4/C13 and C4–C7/C12/C13 rings, respectively.

π⋯π	Distance	Angle of Elevation
Cg1⋯Cg2ⁱ	3.560 (2)	19.56
Cg3⋯Cg2ⁱ	3.644 (2)	22.75
Cg3⋯Cg3ⁱ	3.688 (2)	24.39

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Symmetry code: (i) −x + 1, −y, −z.

supplementary crystallographic information

Comment

4-oxo-1,4-dihydroquinoline-3-carboxylic acid derivatives (quinolones) are an important class of antibacterial agents, and a significant market exists for thiazetoquinoline antibiotics (Matsuoka et al.,1999; Ito et al., 1992; Ito et al., 1994; Ozaki et al., 1991). To this end, the title comound was obtained from the reaction of ethyl 2-{[2- ethoxy-2-oxoethyl)thio)-4-hydroxybenzo[h]quinoline-3-carboxylate with 1,2-dibromopropane in the presence of a catalytic amount of KI, followed by saponification using sodium hydroxide.

The molecular structure of the title molecule is shown in Fig. 1. It exhibits intra- (O5—H5a···O1) and intermolecular (O3—H3···O4ⁱ) hydrogen bonding (Table 1 and Fig. 2) leading to a chain-like arrangement of molecules which run along [201] and perpendicular to the π stacks (Fig. 2). Centroid-centroid distances range from 3.560 (2) to 3.688 (2) Å with angles of elevation between 19.56 and 24.39° (Table 2), while the inter-planar distance, as defined by the adjacent 14-atom (N1,C1—C13) ring system is 3.34 (1) Å.

Experimental

To a mixture of ethyl 2-{[2- ethoxy-2-oxoethyl)thio)-4-hydroxybenzo[h]quinoline-3-carboxylate (1 mmol) and K₂CO₃ (2.8 mmol) in dry DMF (25 ml) under a nitrogen atmosphere was added 1,2-dibromopropane (2.8 mmol) along with a catlytic amount of KI. The reaction mixture was heated at 343 K for 24 h, and then poured into ice-H₂O. The resulting thiazetoquinoline derivative was collected by filtration. The separated product was reacted with sodium hydroxide (2.2 mmol) in water (20 ml) and heated at 373 K for 3–4 h. After being cooled, the reaction mixture was neutralized with hydrochloric acid (1 mol/L), extracted with CH₂Cl₂, dried over MgSO₄, and then evaporated. The obtained solid was purified by recrystallization from ethanol to afford the title compound as a yellowish white powder. Mp. 508 K, yield = 39%. ¹H-NMR and ¹³C-NMR data are given in the archived CIF.