1-Cyclo­propyl-6-fluoro-7-(4-nitro­so­piperazin-1-yl)-4-oxo-1,4-dihydro­quinoline-3-carboxylic acid

Tao Li; Li-Rong Tang; Qiao-Ling Zeng; Wei-Jin Chen; Biao Huang

doi:10.1107/S1600536809029729

. 2009 Jul 31;65(Pt 8):o2053. doi: 10.1107/S1600536809029729

1-Cyclopropyl-6-fluoro-7-(4-nitrosopiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid

Tao Li ^a, Li-Rong Tang ^b, Qiao-Ling Zeng ^b, Wei-Jin Chen ^a, Biao Huang ^b,^*

PMCID: PMC2977261 PMID: 21583715

Abstract

The title compound, C₁₇H₁₇FN₄O₄, is a derivative of ciprofloxacin [1-cyclopropyl-6-fluoro-4-oxo-7-(1-piperazinyl)-1,4-dihydroquinoline-3-carboxylic acid]. The crystal packing is stabilized by intermolecular C—H⋯O hydrogen bonds together with π–π electron ring interactions [centroid–centroid separations between quinoline rings of 3.5864 (11) and 3.9339 (13) Å]. A strong intramolecular O—H⋯O hydrogen bonds is present as well as an intramolecular C—H⋯F interaction.

Related literature

For the biological activity of ciprofloxacin compounds, see: Neu (1987 ▶). For related structures, see: Turel et al. (1996 ▶); Drevenšek et al. (2003 ▶); Li et al. (2005 ▶); Lou et al. (2007 ▶). The nitroso-group geometry is similar to that observed in 1,4-dinitrosopiperazine, see: Sekido et al. (1985 ▶).

Experimental

Crystal data

C₁₇H₁₇FN₄O₄
M _r = 360.35
Triclinic,
a = 8.378 (3) Å
b = 9.625 (4) Å
c = 10.328 (4) Å
α = 102.99 (2)°
β = 96.089 (14)°
γ = 97.392 (16)°
V = 797.0 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 293 K
0.2 × 0.2 × 0.2 mm

Data collection

Rigaku Mercury CCD/AFC diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2007 ▶) T _min = 0.976, T _max = 0.977
6267 measured reflections
3631 independent reflections
2568 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.067
wR(F ²) = 0.207
S = 1.06
3631 reflections
236 parameters
H-atom parameters constrained
Δρ_max = 0.52 e Å⁻³
Δρ_min = −0.35 e Å⁻³

Data collection: CrystalClear (Rigaku, 2007 ▶); 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: SHELXL97 and DIAMOND (Brandenburg, 2005 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809029729/fb2160sup1.cif

e-65-o2053-sup1.cif^{(18.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809029729/fb2160Isup2.hkl

e-65-o2053-Isup2.hkl^{(178KB, 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
O2—H18⋯O3	0.84	1.78	2.562 (2)	153
C15—H15A⋯O2ⁱ	0.99	2.50	3.405 (3)	151
C15—H15B⋯O3ⁱⁱ	0.99	2.51	3.385 (3)	147
C16—H16A⋯O1ⁱⁱⁱ	0.99	2.60	3.264 (3)	125
C16—H16B⋯F1	0.99	2.14	2.852 (3)	128

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

Acknowledgments

The work was supported by a grant from the National Science Foundation of China (30771682).

supplementary crystallographic information

Comment

Ciprofloxacin (1-cyclopropyl-6-fluoro -1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid) is used as an antibacterial agent. Ciprofloxacin is widely used in clinical practice for the treatment of certain diseases caused by some Gram negative and as well as Gram positive microorganisms (Neu, 1987). Recently, several structures containing ciprofloxacin have been reported (Turel et al., 1996; Drevenšek et al., 2003; Lou et al., 2007).

Nitrosation of amines by nitrites takes place in acid medium. The nature of the product depends on the nature of the initial amine. Commonly the secondary alkyl amines yield N-nitrosoamines. In our case, the N-nitrosation of ciprofloxacin occurs by ytterbium nitrate in nitric acid and results in the formation of ON-ciprofloxacin under hydrothermal reaction.

The title compound is composed of an essentially planar quinoline ring system [the mean deviation from best plane is 0.0274 (2) Å] which is substituted with cyclopropyl, fluoro, oxo, carboxyl and nitrosopiperazinium groups (Fig. 1). The bond distances and angles are in agreement with those in 1-cyclopropyl-6-fluoro-7- (4-formylpiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (Li et al., 2005).

In the title structure, the six-membered piperazinyl ring adopts a chair conformation. The nitroso-group geometry with the NO distance equal to 1.2382 (31) Å and O—N—N bond angle of 115.583 (20)° is similar to that observed in 1,4-dinitrosopiperazine (Sekido et al., 1985).

For the hydrogen bonding, please see Tab. 1 that comprises intramolecular and intermolecular hydrogen bonds in the structure (Fig. 2). As shown in Fig. 3, the crystal packing is stabilized by π-π stacking interactions of the quinoline rings, in which the N1 ring (N1/C4—C6/C7—C13) stacks with the inversion-related N1 rings, with the centroid-centroid separations of 3.5864 (11) and 3.9339 (13) Å.

Experimental

The title compound was hydrothermally synthesized under autogenous pressure. A mixture of C₁₇H₁₈FN₃O₃.HCl (ciprofloxacin hydrochloride) (50 mg, 0.14 mmol), Yb(NO₃)₃ (72 mg, 0.2 mmol), HNO₃ (1 ml of 0.5 M), C₂H₅OH (4 ml) and H₂O (8 ml) was sealed in a stainless reactor with a Teflon liner. The mixture was heated to 393 K for one day. After cooling at a rate of 10 K h^-1 to room temperature, yellow needle crystals (average 4 mm long by 0.6 mm diameter) were separated by filtration, washed with distilled water and finally dried in air. Yield 75%, Anal. calc. for C₁₇H₁₇FN₄O₄: C, 56.66; H, 4.76; N, 15.55%; Found: C, 56.82; H, 4.75; N, 15.63%. IR (KBr pellet): 1719(s), 1627(s), 1489(m), 1454(m), 1334(m), 1339(m), 1257(s), 1152(m), 994(m), 896(m), 798(m), 743(m).