1-Ethyl-6-fluoro-7-(4-methyl­piperazin-4-ium-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate hexa­hydrate

Zhe An; Qing-Cheng Liang

doi:10.1107/S1600536808000421

. 2008 Jan 16;64(Pt 2):o441. doi: 10.1107/S1600536808000421

1-Ethyl-6-fluoro-7-(4-methylpiperazin-4-ium-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate hexahydrate

Zhe An ^a, Qing-Cheng Liang ^b,^*

PMCID: PMC2960169 PMID: 21201468

Abstract

In the title compound, C₁₇H₂₀FN₃O₃·6H₂O, the pefloxacin (pef) neutral zwitterion is accompanied by six water molecules of hydration. An extensive network of O—H⋯O and N—H⋯O hydrogen bonds help to establish the crystal packing.

Related literature

For metal complexes of the pef anion, see: Baenziger et al. (1986 ▶); An, Huang & Qi (2007 ▶); An, Qi & Huang (2007 ▶). For background on the medicinal uses of Hpef, see: Mizuki et al. (1996 ▶).

Experimental

Crystal data

C₁₇H₂₀FN₃O₃·6H₂O
M _r = 441.46
Monoclinic,
a = 8.0925 (15) Å
b = 24.075 (5) Å
c = 10.8006 (19) Å
β = 92.064 (3)°
V = 2102.9 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 296 (2) K
0.34 × 0.26 × 0.18 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.960, T _max = 0.978
10920 measured reflections
3743 independent reflections
2239 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.134
S = 1.02
3743 reflections
312 parameters
19 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Bruker, 1998 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808000421/hb2680sup1.cif

e-64-0o441-sup1.cif^{(22KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808000421/hb2680Isup2.hkl

e-64-0o441-Isup2.hkl^{(183.5KB, 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
O1W—H1W1⋯O1	0.857 (10)	1.866 (12)	2.700 (3)	164 (3)
O1W—H1W2⋯O3W	0.85 (3)	2.201 (16)	3.017 (3)	162 (3)
O2W—H2W1⋯O2	0.851 (10)	1.881 (13)	2.722 (3)	170 (4)
O2W—H2W2⋯O6W	0.86 (3)	1.91 (3)	2.765 (3)	171 (3)
O3W—H3W2⋯O1ⁱ	0.852 (10)	1.896 (13)	2.730 (3)	166 (3)
O3W—H3W1⋯O2W	0.86 (3)	1.82 (3)	2.679 (3)	175 (3)
O6W—H6W1⋯O1Wⁱ	0.86 (3)	1.92 (3)	2.765 (4)	170 (4)
O6W—H6W2⋯O4Wⁱⁱ	0.847 (10)	2.17 (3)	3.007 (4)	170 (4)
N3—H3N⋯O3Wⁱⁱⁱ	0.910 (10)	1.847 (13)	2.730 (3)	163 (3)
O4W—H4W1⋯O3	0.86 (3)	1.89 (3)	2.739 (3)	169 (3)
O4W—H4W2⋯O5Wⁱⁱ	0.85 (3)	1.959 (15)	2.783 (3)	163 (3)
O5W—H5W1⋯O2	0.85 (3)	1.97 (3)	2.792 (3)	164 (4)
O5W—H5W1⋯O3	0.85 (3)	2.63 (4)	3.142 (3)	120 (3)
O5W—H5W2⋯O5Wⁱⁱ	0.84 (3)	2.06 (2)	2.769 (5)	142 (3)

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

Acknowledgments

The authors acknowledge financial support by the Science Foundation of Heilongjiang Provincial Department of Science & Technology (grant No. GC07C35204).

supplementary crystallographic information

Comment

Pefloxacin (Hpef, C₁₇H₂₀FN₃O₃, 1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)-4-oxo-quinoline -3-carboxylic acid) is member of a class of quinolones used to treat infections (Mizuki et al., 1996). The silver(I), manganese(II) and cobalt(II) derivatives of the pefloxacin (pef) anion have been reported (Baenziger et al., 1986; An, Huang & Qi, 2007; An, Qi & Huang, 2007).

We attempted to prepare a nickel(II) complex of pef, but the title compound, (I), arose instead. The neutral Hpef zwitterion shows nominal proton transfer from O1 or O2 to N3. Consequently the C1—O1 [1.264 (3) Å] and C1—O2 [1.245 (3) Å] bond lengths are very similar. The bond angle sum for N1 of 360° indicates sp² hybridization for this atom. The N2/N3/C11—C14 ring is a typical chair.

The components of (I) are linked by O—H···O and O—H···N hydrogen bonds (Table 1) involving all the potential donors, generating a three-dimensional supramolecular network.

Experimental

A mixture of Ni(NO₃)₂.6H₂O (0.075 g, 0.25 mmol), Hpef (0.17 g, 0.5 mmol), and water (12 ml) was stirred for 30 min in air. The mixture was then transferred to a 23 ml Teflon-lined hydrothermal bomb. The bomb was kept at 423 K for 72 h under autogenous pressure. The targeted Ni²⁺ complex was not synthesized and colorless prisms of (I) were obtained from the reaction mixture after cooling.