202349-45-9Relevant academic research and scientific papers
Validation of a Chiral Liquid Chromatographic Method for the Degradation Behavior of Flumequine Enantiomers in Mariculture Pond Water
Wang, Yan-Fei,Gao, Xiao-Feng,Jin, Huo-Xi,Wang, Yang-Guang,Wu, Wei-Jian,Ouyang, Xiao-Kun
, p. 649 - 655 (2016)
In this work, flumequine (FLU) enantiomers were separated using a Chiralpak OD-H column, with n-hexane-ethanol (20:80, v/v) as the mobile phase at a flow rate of 0.6 mL/min. Solid phase extraction (SPE) was used for cleanup and enrichment. The limit of detection, limit of quantitation, linearity, precision, and intra/interday variation of the chiral high-performance liquid chromatography (HPLC) method were determined. The developed method was then applied to investigate the degradation behavior of FLU enantiomers in mariculture pond water samples. The results showed that the degradation of FLU enantiomers under natural, sterile, or dark conditions was not enantioselective. Chirality 28:649–655, 2016.
Enantioseparation and determination of flumequine enantiomers in multiple food matrices with chiral liquid chromatography coupled with tandem mass spectrometry
Li, Shuang,Liu, Beibei,Xue, Mengyao,Yu, Jia,Guo, Xingjie
, p. 968 - 978 (2019)
The present work firstly described the enantioseparation and determination of flumequine enantiomers in milk, yogurt, chicken, beef, egg, and honey samples by chiral liquid chromatography-tandem mass spectrometry. The enantioseparation was performed under reversed-phase conditions on a Chiralpak IC column at 20°C. The effects of chiral stationary phase, mobile phase components, and column temperature on the separation of flumequine enantiomers have been studied in detail. Target compounds were extracted from six different matrices with individual extraction procedure followed by cleanup using Cleanert C18 solid phase extraction cartridge. Good linearity (R2>0.9913) was obtained over the concentration range of 0.125 to 12.5 ng g-1 for each enantiomer in matrix-matched standard calibration curves. The limits of detection and limits of quantification of two flumequine enantiomers were 0.015-0.024 and 0.045-0.063 ng g-1, respectively. The average recoveries of the targeted compounds varied from 82.3 to 110.5%, with relative standard deviation less than 11.7%. The method was successfully applied to the determination of flumequine enantiomers in multiple food matrices, providing a reliable method for evaluating the potential risk in animal productions.
Chiral separation and modeling of quinolones on teicoplanin macrocyclic glycopeptide antibiotics CSP
Ali, Imran,Suhail, Mohd,Asnin, Leonid
, p. 1304 - 1311 (2018/10/24)
New chiral high-performance liquid chromatography (HPLC) method for the enantiomeric resolution of quinolones is developed and described. The column used was Chirobiotic T (150?×?4.6?mm, 5.0?μm). Three mobile phases used were MeOH:ACN:Water:TEA (70:10:20:0.1%), (60:30:10:0.1%), and (50:30:20:0.1%). The flow rate of the mobile phases was 1.0?mL/min with UV detection at different wavelengths. The values of retention, resolution, and separation factors ranged from 1.5 to 6.0, 1.80 to 2.25, and 2.86 to 6.0, respectively. The limit of detection and quantification ranged from 4.0 to 12?ng and 40 to 52?ng, respectively. The modeling studies indicated strong interactions of R-enantiomers with teicoplanin chiral selector than S-enantiomers. The supra molecular mechanism of the chiral recognition was established by modeling and chromatographic studies. It was observed that hydrogen bondings and π-π interactions are the major forces for chiral separation. The present chiral HPLC method may be used for enantiomeric resolution of quinolones in any matrices.
Selective Catalytic Hydrogenation of Heteroarenes with N-Graphene-Modified Cobalt Nanoparticles (Co3O4-Co/NGratα-Al2O3)
Chen, Feng,Surkus, Annette-Enrica,He, Lin,Pohl, Marga-Martina,Radnik, J?rg,Topf, Christoph,Junge, Kathrin,Beller, Matthias
, p. 11718 - 11724 (2015/09/28)
Cobalt oxide/cobalt-based nanoparticles featuring a core-shell structure and nitrogen-doped graphene layers on alumina are obtained by pyrolysis of Co(OAc)2/phenanthroline. The resulting core-shell material (Co3O4-Co/NGratα-Al2O3) was successfully applied in the catalytic hydrogenation of a variety of N-heteroarenes including quinolines, acridines, benzo[h], and 1,5-naphthyridine as well as unprotected indoles. The peculiar structure of the novel heterogeneous catalyst enables activation of molecular hydrogen at comparably low temperature. Both high activity and selectivity were achieved in these hydrogenation processes, to give important building blocks for bioactive compounds as well as the pharmaceutical industry.
Asymmetric metal-free synthesis of fluoroquinolones by organocatalytic hydrogenation
Rueping, Magnus,Stoeckel, Mirjam,Sugiono, Erli,Theissmann, Thomas
experimental part, p. 6565 - 6568 (2010/10/19)
A highly enantioselective organocatalytic transfer hydrogenation enabling the synthesis of both 6-fluoro-2-methyltetrahydroquinoline and 7,8-difluoro-3-methyl-benzoxazine has been developed. These key building blocks can for the first time be synthesized using the same methodology allowing fast and efficient, metal-free access to the antibiotic fluoroquinolones flumequine and levofloxacine.
Synthesis, absolute configuration and intermediates of 9-fluoro- 6,7- dihydro-5-methyl-1-oxo-1H,5H-benzo[i.j]quinolizine-2-carboxylic acid (flumequine)
Balint, Jozsef,Egri, Gabriella,Fogassy, Elemer,Boecskei, Zsolt,Simon, Kalman,Gajary, Antal,Friesz, Antal
, p. 1079 - 1087 (2007/10/03)
The antibacterial agent 9-fluoro-6,7-dihydro-5-methyl-1-oxo-1H,5H- benzo[i.j]quinolizine-2-carboxylic acid (flumequine) was synthesized in optically active form from 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline (FTHQ). Racemic FTHQ was resolved with the enantiomers of 3-bromocamphor-8- sulfonic acid. The configurations were established by X-ray structures of the two diastereoisomeric salts. Enantiomeric excesses were determined by 1H NMR analysis.
Process for the synthesis of a benzo [ij] quinolizine-2-carboxylic acid derivative
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, (2008/06/13)
Process for preparing 6,7-dihydro-9-fluoro-5-methyl--1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid (flumequine, I) wherein, 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline (II) is reacted in the presence of a catalyst with an alkyl ortho-formate (IX), wherein R3 represents a C1-C4 alkyl, and with a 2,2-disubstituted 1,3-dioxan-4,6-dione, wherein each R1 and R2, which can be the same or different, represents a hydrogen atom, a branched- or straight-chain C1-C6 alkyl or phenyl, or R1 and R2 together represent a polymethylene group -(CH2)n-, n= 4 or 5, so as to form a 2,2-disubstituted 5- [1-(6-fluoro-2-methyl--1,2,3,4-tetrahydroquinolyl)] methylene-1,3-dioxan--4,6-dione of formula (VII): and then said compound of formula (VII) is reacted in the presence of polyphosphoric acid and ethyl polyphosphate, whereby the desired compound (I) is directly obtained and isolated according to conventional methods.
Process for 6,7-dihydro-9-fluoro-5-methyl-1-oxo-1H,5H-benzo(ij)quinolizine-2-carboxylic acid
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, (2008/06/13)
An improved process for preparing the antimicrobial compound flumequine is disclosed. The first step of the process comprises reacting 4-fluoroaniline with crotonaldehyde under acidic conditions at a temperature between 50° and 60° C. In the second step, the product of the first step is slowly added to a refluxing solvent which forms a binary azeotrope with water and has a boiling point between 90° and 120° C. to provide a mixture of 6-fluoroquinaldine and 6-fluorotetrahydroquinaldine. This mixture is then treated with base in the presence of weak acid followed by reducing to provide 6-fluorotetrahydroquinaldine. This compound is then treated according to known procedures to form flumequine.
Process for 6,7-dihydro-9-fluoro-5-methyl-1-oxo-1H,5H-benzo(ij)quinolizine-2-carboxylic acid
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, (2008/06/13)
An improved process for preparing the antimicrobial compound flumequine is disclosed. The first step of the process comprises reacting 4-fluoroaniline with crotonaldehyde under acidic conditions at a temperature between 50° and 60° C. In the second step, the product of the first step is treated to provide a mixture of 6-fluoroquinaldine and 6-fluorotetrahydroquinaldine. This mixture is then treated with base in the presence of weak acid followed by reducing to provide 6-fluorotetrahydroquinaldine. This compound is then treated according to known procedures to form flumequine.
Intermediates for 6,7-dihydro-9-fluoro-5-methyl-1-oxo-1H,5H-benzo(ij)quinolizine-2-carboxylic acid
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, (2008/06/13)
Intermediates in a process for preparing the antimicrobial compound flumequine are disclosed. The intermediates have the following formula STR1 wherein R is hydrogen or alkyl having 1-3 carbon atoms and acid addition salts thereof.
