70458-92-3

Basic information

• Product Name: Pefloxacin
• Synonyms: RB-1589;PEFLOXACIN;PEFLOXACINE MESYLATE DIHYDRATE;PEFLOXACINE METHANSULFONATE DIHYDRATE;PEFLOXACIN MESYLATE DIHYDRATE;PEFLOXACIN METHANESULFONATE;PEFLOXACIN METHANE SULFONATE DIHYDRATE;PERFLOXACINE
• CAS NO: 70458-92-3
• Molecular Formula: C₁₇H₂₀FN₃O₃
• Molecular Weight: 333.36
• EINECS: 274-611-8
• Mol File: 70458-92-3.mol

Chemical Properties

• Melting Point: 270-272° (dec)
• Boiling Point: 529.1 °C at 760 mmHg
• Flash Point: 273.8 °C
• Appearance: /
• Density: 1.32 g/cm³
• Vapor Pressure: 5.05E-12mmHg at 25°C
• Refractive Index: 1.593
• Storage Temp.: 2-8°C
• Solubility: Aqueous Acid (Slightly), Methanol (Slightly), Water (Slightly)
• PKA: 0.16±0.20(Predicted)
• CAS DataBase Reference: Pefloxacin(CAS DataBase Reference)
• NIST Chemistry Reference: Pefloxacin(70458-92-3)
• EPA Substance Registry System: Pefloxacin(70458-92-3)

Safety Data

• Hazardous Substances Data: 70458-92-3(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
Pefloxacin is used as an antibacterial agent for treating various bacterial infections. Its application is particularly effective against a wide range of gram-negative and gram-positive bacteria, making it a versatile choice for combating infections.
Used as a DNA Gyrase Inhibitor:
In the field of molecular biology and pharmaceutical research, Pefloxacin is utilized as a DNA gyrase inhibitor. It interferes with the essential enzyme responsible for bacterial DNA replication, thus inhibiting bacterial growth and playing a crucial role in the development of new antibiotics and understanding the mechanisms of bacterial resistance.

Pharmaceutical Applications

A 6-fluoro, 7-piperazinyl quinoline available for oral and intravenous administration. The in-vitro activity is very similar to that of norfloxacin . It is active against H. ducreyi, V. cholerae and Legionella spp., but Campylobacter and Acinetobacter spp. and pseudomonads are not susceptible. It has poor activity against pneumococci, chlamydiae, mycoplasmas and ureaplasmas. L. monocytogenes, Nocardia spp. and anaerobes are resistant.A plasma concentration of c. 5 mg/L is achieved 1–1.5 h after a 400 mg oral dose. The plasma elimination half-life is 8.5–15 h. It is widely distributed, concentrations in bone, brain, blister fluid, CSF, saliva, sputum and prostate all approximating, and in some cases exceeding, the simultaneous plasma concentration. It is extensively metabolized to the desmethyl (= norfloxacin) and N-oxide derivatives. Some 60–70% of a dose, only about 10% of which is unchanged, appears in the urine; 25% of a dose appears in the feces, a small part contributed by elimination in the bile.The half-life increases with hepatic impairment, but is virtually unaffected by renal failure. In patients on continuous ambulatory peritoneal dialysis (CAPD) given 800 mg followed by 400 mg every 12 h for 10–12 days, there was no significant accumulation of pefloxacin or its metabolite, norfloxacin, but concentrations of pefloxacin N-oxide rose continuously in plasma and dialysate; all concentrations fell rapidly when treatment was discontinued.Adverse reactions are those common to the group . Most common are gastrointestinal tract disturbances, although some typical CNS reactions have been encountered. Skin eruptions (some photosensitive) occur and rashes appeared in about one-third of a group of patients who were given longterm therapy. Clinical uses are similar to those of ofloxacin.

InChI:InChI=1/C17H20FN3O3/c1-3-20-10-12(17(23)24)16(22)11-8-13(18)15(9-14(11)20)21-6-4-19(2)5-7-21/h8-10H,3-7H2,1-2H3,(H,23,24)

Synthetic route

1-methyl-piperazine (109-01-3) + 7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (68077-26-9) → Pefloxacin (70458-92-3) + 7-Chloro-1-ethyl-6-(4-methyl-piperazin-1-yl)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid

Conditions	Yield
In water for 13h; Heating;	A 90% B n/a
In dimethylsulfoxide-d6 at 120 - 130℃;	A 82 % Spectr. B 18 % Spectr.

formaldehyd (50-00-0) + 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (70458-96-7) → Pefloxacin (70458-92-3)

Conditions	Yield
With formic acid Heating;	85%

4-(t-butyldimethylsilyl)-1-methyl piperazine + 7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (68077-26-9) + tetra-n-butylammoniumfluoride trihydrate (22206-57-1) → Pefloxacin (70458-92-3)

Conditions	Yield
In water; acetonitrile	85%

1-methyl-piperazine (109-01-3) + 7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (68077-26-9) → Pefloxacin (70458-92-3)

Conditions	Yield
at 130 - 140℃; for 5h;	68%

1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (70458-96-7) + methyl iodide (74-88-4) → Pefloxacin (70458-92-3)

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 80 - 90℃; for 2h;	30%

1-methyl-piperazine (109-01-3) + 6,7-difluoro-1-ethyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (70032-25-6) → Pefloxacin (70458-92-3)

Conditions	Yield
Yield given. Multistep reaction;
In dimethyl sulfoxide at 40℃; Rate constant; or over the mixed anhydrides with BF3 or BBr3 (facilitate the aromatic substitution);

methyl bromide (74-83-9) + 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (70458-96-7) → Pefloxacin (70458-92-3)

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 80 - 90℃; for 2h;

1-methyl-piperazine (109-01-3) + C16H14BClFNO7 → Pefloxacin (70458-92-3)

Conditions	Yield
With sodium hydroxide 1.) DMSO, 110 deg C, 2 h; 2.) reflux, 1 h; Yield given;

3-chloro-4-fluorophenylamine (367-21-5) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 6 steps 1: 100 percent / 2 h / 120 - 130 °C 2: diphenyl ether / 1 h / Heating 3: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 4: 90 percent / 2N NaOH / 2 h / Heating 5: 66 percent / 5 h / 130 - 140 °C 6: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 6 steps 1: 100 percent / 2 h / 120 - 130 °C 2: diphenyl ether / 1 h / Heating 3: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 4: 90 percent / 2N NaOH / 2 h / Heating 5: 66 percent / 5 h / 130 - 140 °C 6: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme
Multi-step reaction with 5 steps 1: 100 percent / 2 h / 120 - 130 °C 2: diphenyl ether / 1 h / Heating 3: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 4: 90 percent / 2N NaOH / 2 h / Heating 5: 68 percent / 5 h / 130 - 140 °C View Scheme

7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (68077-26-9) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 66 percent / 5 h / 130 - 140 °C 2: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 2 steps 1: 66 percent / 5 h / 130 - 140 °C 2: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme

1-ethyl-6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester (70458-94-5) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: 90 percent / 2N NaOH / 2 h / Heating 2: 66 percent / 5 h / 130 - 140 °C 3: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 3 steps 1: 90 percent / 2N NaOH / 2 h / Heating 2: 66 percent / 5 h / 130 - 140 °C 3: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme
Multi-step reaction with 2 steps 1: 90 percent / 2N NaOH / 2 h / Heating 2: 68 percent / 5 h / 130 - 140 °C View Scheme

ethyl 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate (74011-47-5) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 2N NaOH / 2 h / Heating 2: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 2 steps 1: 2N NaOH / 2 h / Heating 2: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme

diethyl 2-[(3-chloro-4-fluorophenylamino)methylene]malonate (70032-30-3) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 5 steps 1: diphenyl ether / 1 h / Heating 2: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 3: 90 percent / 2N NaOH / 2 h / Heating 4: 66 percent / 5 h / 130 - 140 °C 5: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 5 steps 1: diphenyl ether / 1 h / Heating 2: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 3: 90 percent / 2N NaOH / 2 h / Heating 4: 66 percent / 5 h / 130 - 140 °C 5: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme
Multi-step reaction with 4 steps 1: diphenyl ether / 1 h / Heating 2: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 3: 90 percent / 2N NaOH / 2 h / Heating 4: 68 percent / 5 h / 130 - 140 °C View Scheme

7-Chloro-6-fluoro-4-hydroxy-3-quinolinecarboxylic acid ethyl ester (70458-93-4) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 4 steps 1: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 2: 90 percent / 2N NaOH / 2 h / Heating 3: 66 percent / 5 h / 130 - 140 °C 4: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 4 steps 1: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 2: 90 percent / 2N NaOH / 2 h / Heating 3: 66 percent / 5 h / 130 - 140 °C 4: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme
Multi-step reaction with 3 steps 1: 90 percent / K2CO3 / dimethylformamide / 10 h / 80 - 90 °C 2: 90 percent / 2N NaOH / 2 h / Heating 3: 68 percent / 5 h / 130 - 140 °C View Scheme

6-Fluoro-4-hydroxy-7-piperazin-1-yl-quinoline-3-carboxylic acid ethyl ester (75001-56-8) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: K2CO3 / dimethylformamide / 2 h / 60 - 90 °C 2: 2N NaOH / 2 h / Heating 3: 85 percent / 87percent HCOOH / Heating View Scheme
Multi-step reaction with 3 steps 1: K2CO3 / dimethylformamide / 2 h / 60 - 90 °C 2: 2N NaOH / 2 h / Heating 3: 30 percent / Et3N / dimethylformamide / 2 h / 80 - 90 °C View Scheme

N-ethyl-3,4-difluoroaniline (136491-15-1) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: 62 percent / 0.5 h / 90 - 100 °C 2: 71 percent / PPA / toluene / 0.58 h / 100 °C 3: dimethylsulfoxide / 40 °C / or over the mixed anhydrides with BF3 or BBr3 (facilitate the aromatic substitution) View Scheme

N-(3,4-Difluorphenyl)-N-ethyl-formamid (136491-16-2) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 4 steps 1: 77 percent / conc. HCl / H2O / 2 h / Heating 2: 62 percent / 0.5 h / 90 - 100 °C 3: 71 percent / PPA / toluene / 0.58 h / 100 °C 4: dimethylsulfoxide / 40 °C / or over the mixed anhydrides with BF3 or BBr3 (facilitate the aromatic substitution) View Scheme

N-(3,4-Difluorphenyl)-N-ethyl-aminomethylen-meldrumsaeure (136491-17-3) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 71 percent / PPA / toluene / 0.58 h / 100 °C 2: dimethylsulfoxide / 40 °C / or over the mixed anhydrides with BF3 or BBr3 (facilitate the aromatic substitution) View Scheme

3,4-difluoroaniline (3863-11-4) → Pefloxacin (70458-92-3)

Conditions	Yield
Multi-step reaction with 5 steps 1: 72.5 percent / conc. H2SO4 / 1.5 h / 175 °C 2: 77 percent / conc. HCl / H2O / 2 h / Heating 3: 62 percent / 0.5 h / 90 - 100 °C 4: 71 percent / PPA / toluene / 0.58 h / 100 °C 5: dimethylsulfoxide / 40 °C / or over the mixed anhydrides with BF3 or BBr3 (facilitate the aromatic substitution) View Scheme

1-methyl-piperazine (109-01-3) + 7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (68077-26-9) + pyrographite (7440-44-0) → Pefloxacin (70458-92-3)

Conditions	Yield
In acetic acid; dimethyl sulfoxide

1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinolinecarboxylic acid methanesulfonate dihydrate → Pefloxacin (70458-92-3)

Conditions	Yield
With ammonia In water

RuCl2*3H2O + water (7732-18-5) + Pefloxacin (70458-92-3) → [Ru(PEF)Cl2(H2O)2]*5H2O

Conditions	Yield
In methanol for 24h; Reflux;	91%

iron(III) chloride hexahydrate + water (7732-18-5) + Pefloxacin (70458-92-3) → [Fe(PEF)Cl2(H2O)2]*5H2O

Conditions	Yield
In methanol for 24h; Reflux;	86%

methanol (67-56-1) + 1,10-Phenanthroline (66-71-7) + copper(II) choride dihydrate + Pefloxacin (70458-92-3) → C29H27ClCuFN5O3*CH4O*2H2O

Conditions	Yield
Stage #1: Pefloxacin With potassium hydroxide In methanol for 0.5h; Stage #2: methanol; 1,10-Phenanthroline; copper(II) choride dihydrate for 0.333333h;	85%

Pefloxacin (70458-92-3) + 1,1'-carbonyldiimidazole (530-62-1) → 1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)-3-(1H-imidazole-1-formyl)quinoline-4(1H)-one

Conditions	Yield
In acetonitrile Solvent; Reflux;	83.5%

hydrogen bromide (10035-10-6, 12258-64-9) + Pefloxacin (70458-92-3) + zinc(II) oxide → pefloxancindium tetrabromidozincate (1368704-55-5)

Conditions	Yield
In hydrogen bromide aq. HBr; pefloxacin dissolved in 6 M HBr; ZnO was slowly added to molar ratio Zn:pefloxacin = 2:1; solvent evapd.; crystals were obtained; elem. anal.;	83%

water (7732-18-5) + Pefloxacin (70458-92-3) + zinc(II) chloride (7646-85-7) → [Zn(PEF)Cl(H2O)]

Conditions	Yield
In methanol for 24h; Reflux;	82%

copper(II) chloride hydrate + water (7732-18-5) + Pefloxacin (70458-92-3) → [Cu(PEF)2]*4H2O

Conditions	Yield
In methanol for 24h; Reflux;	80%

Pefloxacin (70458-92-3) → 1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)-2,3-dihydroquinolin-4(1Η)-one (110719-52-3)

Conditions	Yield
With sodium tetrahydroborate; toluene-4-sulfonic acid In methanol at 65℃; for 0.5h;	76.2%
Stage #1: Pefloxacin With methanol; sodium tetrahydroborate at 0℃; for 1h; Stage #2: With toluene-4-sulfonic acid at 60 - 65℃; for 0.5h;	76.3%

vanadium(IV) fluoride (10049-16-8) + Pefloxacin (70458-92-3) → difluorovanadium(IV) di(1-ethyl-6-fluoro-1,4-dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinoline carboxylate)

Conditions	Yield
In methanol methanolic soln. of VF4 added to methanolic soln. of C17H22O3N3F dropwise with stirring, mixt. had pH 3, refluxed for 2 h, kept overnight with stirring at room temp.; solvent removed on a rotary apparatus under reduced pressure; recrystn. (MeOH/n-hexane, 1/1); elem. anal.;	76%

methanol (67-56-1) + copper(II) choride dihydrate + Pefloxacin (70458-92-3) → C35H42CuF2N6O7

Conditions	Yield
Stage #1: Pefloxacin With potassium hydroxide In methanol for 0.5h; Stage #2: methanol; copper(II) choride dihydrate for 0.5h;	75%

methanol (67-56-1) + [2,2]bipyridinyl (366-18-7) + copper(II) choride dihydrate + Pefloxacin (70458-92-3) → C27H27ClCuFN5O3*0.5CH4O*4H2O

Conditions	Yield
Stage #1: Pefloxacin With potassium hydroxide In methanol for 0.5h; Stage #2: methanol; [2,2]bipyridinyl; copper(II) choride dihydrate for 0.333333h;	75%

K2PtCl4 + water (7732-18-5) + Pefloxacin (70458-92-3) → [Pt(PEF)Cl(H2O)]*3H2O

Conditions	Yield
In methanol for 24h; Reflux;	74%

methanol (67-56-1) + Pefloxacin (70458-92-3) → pefloxacin

Conditions	Yield
With sulfuric acid for 12h; Reflux;	73%

di(pyridin-2-yl)amine (1202-34-2) + copper(II) choride dihydrate + Pefloxacin (70458-92-3) → C27H28ClCuFN6O3*2H2O

Conditions	Yield
Stage #1: Pefloxacin With potassium hydroxide In methanol for 0.5h; Stage #2: di(pyridin-2-yl)amine; copper(II) choride dihydrate In methanol for 0.333333h;	70%

copper(II) choride dihydrate + water (7732-18-5) + levofloxacin (100986-85-4) + Pefloxacin (70458-92-3) → (levofloxacin)(bipyridyl amine)CuCl2*5H2O

Conditions	Yield
With CH3ONa In methanol CH3OH soln. of Cu salt added to CH3OH soln. of bipyridyl amine (1:1), treated with 1 equiv. of levofloxacin in CH3OH, pH adjusted to 6.2 (CH3ONa), refluxed for 1 h; concd., washed (cold CH3OH, ether), dried (vac.), elem. anal.;	68%

di(pyridin-2-yl)amine (1202-34-2) + copper(II) choride dihydrate + water (7732-18-5) + Pefloxacin (70458-92-3) → pefloxaci

Conditions	Yield
With CH3ONa In methanol CH3OH soln. of Cu salt added to CH3OH soln. of bipyridyl amine (1:1), treated with 1 equiv. of pefloxacin in CH3OH, pH adjusted to 6.2 (CH3ONa),refluxed for 1 h; concd., washed (cold CH3OH, ether), dried (vac.), elem. anal.;	63%

copper(II) choride dihydrate + C9H6ClN3OS2 + water (7732-18-5) + Pefloxacin (70458-92-3) → C26H24ClCuFN6O4S2*H2O

Conditions	Yield
With sodium methylate In methanol for 3h; pH=Ca. 6.8; Reflux;	61.2%

[tris(triphenylphosphine) ruthenium(III) trichloride] (30050-39-6, 23311-38-8) + Pefloxacin (70458-92-3) → [Ru(pefloxacin-(1H))(PPh3)2Cl2]

Conditions	Yield
With sodium methylate In methanol; toluene Reflux;	57.9%

oxovanadium(IV) sulfate + Pefloxacin (70458-92-3) + 3-(diphenylphosphino)propionic acid (2848-01-3) → C30H29FN3O6PV

Conditions	Yield
In methanol for 10h; pH=Ca. 6.8; Reflux;	57.32%

[tris(triphenylphosphine) ruthenium(III) trichloride] (30050-39-6, 23311-38-8) + Pefloxacin (70458-92-3) → [Ru(pefloxacin-(1H))(PPh3)3Cl]

Conditions	Yield
With sodium methylate; triethylamine; lithium chloride In methanol; toluene Reflux;	53.8%

4,6-dihydroxy-2-mercaptopyrimidine (504-17-6) + Pefloxacin (70458-92-3) → pefloxacinium 2-thiobarbiturate

Conditions	Yield
In water at 80℃;	53%

copper(II) choride dihydrate + Pefloxacin (70458-92-3) + 3-(diphenylphosphino)propionic acid (2848-01-3) → C32H33CuFN3O5P*H2O

Conditions	Yield
With sodium methylate In methanol for 3h; pH=Ca. 6.8; Reflux;	52.3%

BARBITURIC ACID (67-52-7) + Pefloxacin (70458-92-3) → bis(pefloxacinium 2-thiobarbiturate) hydrate

Conditions	Yield
With water at 80℃;	43%

3-(1-amino-5-mercapto-1H-[1,3,4]triazol-2-yl)-1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4(1H)quinolinone (1215036-45-5) + Pefloxacin (70458-92-3) → C37H40F2N10O2S*2ClH

Conditions	Yield
With dmap; trichlorophosphate at 20℃; Reflux;	34%

Upstream product

• 109-01-3 1-methyl-piperazine 
• 70032-25-6 6,7-difluoro-1-ethyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 
• 68077-26-9 7-chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 
• 50-00-0 formaldehyd 
• 70458-96-7 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid 
• 74-88-4 methyl iodide 
• 74-83-9 methyl bromide 
• 70458-94-5 1-ethyl-6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester 
• 74011-47-5 ethyl 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate 
• 70032-30-3 diethyl 2-[(3-chloro-4-fluorophenylamino)methylene]malonate 
• 22206-57-1 tetra-n-butylammoniumfluoride trihydrate 
• 7440-44-0 pyrographite 
• 149676-40-4 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinolinecarboxylic acid methanesulfonate dihydrate 
• 3863-11-4 3,4-difluoroaniline 

Downstream Products

• 110719-58-9 1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)quinolin-4(1Η)-one-3-carboxaldehyde 

Relevant articles and documents

Biophysical models as an approach to study passive absorption in drug development: 6-fluoroquinolones

A preliminary study attempting to assess and explain the intestinal absorption of a series of antibacterial 7-piperazinyl-6-fluoroquinolones is presented. The synthesis, n-octanol partition coefficients, intrinsic rat gut in situ absorption rate constants, and in vitro antibacterial activity data found for these homologous compounds are described. A fluorimetric, reverse- phase HPLC method was performed for the quantification of the quinolones in absorption and partition samples. Equations based on two classic biophysical absorption models are given for predicting the intrinsic absorption features of the series according to the partition data or merely single structural parameters. In situ absorption rate constants were found to increase by a factor of 9.7-13.5 for moderately lipophilic derivatives relative to the simplest compound, while antibacterial activity decreased only by a factor of 4. In vivo absorption tests with two representative members of the series were carried out and the results showed a good accordance with those found in situ. This makes these compounds or related ones with similar partition features excellent candidates for further pharmacokinetic and pharmacological testing. The study can serve as an example of how to prevent potential absorption problems associated with the development of new drugs.

Synthesis and structure of C17H22FN3O32+ · CuCl42-

A new compound C17H22FN3O32+ · CuCl42- [pefloxacindium tetrachlorocuprate(II)], C17H20FN3O3 - 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinoline carboxylic acid (pefloxacin, PefH) is synthesized and characterized by single crystal X-ray diffraction technique. The crystal structure of the compound contains one PefH32+ cation and one CuCl42- anion. The supramolecular architecture of the crystal is determined.

NOVEL METHOD OF SYNTHESIS OF FLUOROQUINOLONES

The invention relates to a method of preparation of fluoroquinolones of formula (I) from compounds of formula (II): in which R1, R2, R3, R4, R5, R6, R7, and X are as defined in Claim 1.

Convenient one pot synthesis of some fluoroquinolones in aqueous media

A one pot synthetic strategy for the preparation of fluoroquinolones from 1 is introduced. Product 3 was condensed with piperazine in an aqueous media to produce pharmaceutical grade ciprofloxacin in 86% yield. The method was extended to the synthesis of some other fluoroquinolones with pharmaceutical grade quality.

Regioselective nucleophilic substitution of halogen derivatives of 1-substituted 4-oxo-1,4-dihydroquinoline-3-carboxylic acids

The rate of the nucleophilic displacement of the fluoro atom of 7-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate could be enhanced either by the introduction of further fluoro atom(s) into position(s) 6 and/or 8, or by the formation of a boron chelate (e.g. 3). The regioselectivity of the nucleophilic substitution of the chloro atom in 1-substituted 6-fluoro-7-chloro-4-oxo-1,4dihydroquinoline-3-carboxylic acids could also be enhanced by the formation of a boron chelate (e.g. 7).

Process for the preparation of quinolonecarboxylic acid esters

A process for the preparation of quinolone-carboxylic acid esters of the formulae I and II STR1 in which A represents nitrogen or =C--R4, R4 represents hydrogen, fluorine, chlorine, nitro or methyl, B represents halogen, nitro, alkoxy, alkylsulphonyloxy or the radical STR2 and B additionally represents STR3 if R1 does not denote cyclopropyl, and R5 represents a branched or unbranched alkyl group which has 1 to 4 carbon atoms and which can optionally be substituted by a hydroxyl or methoxy group, R6 represents hydrogen, methyl or phenyl, R7 represents hydrogen or methyl, R8 represents dialkylamino having 1 or 2 carbon atoms in the alkyl group or dialkylaminomethyl having 1 or 2 carbon atoms in the alkyl group, or aminomethyl R1 represents hydrogen, optionally substituted alkyl having 1 to 3 carbon atoms, optionally substituted cycloalkyl, 2-fluoroethyl, vinyl, methoxy or 4-fluorophenyl, R2 represents optionally substituted alkyl having 1 to 6 carbon atoms and also cyclohexyl and benzyl, R3 represents hydrogen, methyl or ethyl, and Z represents oxygen, nitrogen which is substituted by methyl or phenyl, and =CH2, characterized in that quinolonecarboxylic acids of the formulae III and IV STR4 in which A, B, Z, R1 and R3 have the meanings indicated above, are reacted with chloroformic acid esters of the formula V in which R2 has the meaning indicated above.

Synthesis of Novel Quinolone-Chemotherapeutics. V. Methodical Investigations on the Synthesis of Quinolone Chemotherapeutics

The synthesis of 6,7-dihalogen-N-ethyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acids (3a,b) from 3,4-dihalogen-anilines is a three-step processes: (a) N-ethylation, (b) reaction with orthoformic ester and Meldrum's acid, (c) intramolecular cyclization.An increase of the total yields in comparison with known methods is mainly connected with the third step.Here the Meldrum's method allows reactions in solution at temperatures 100 deg C.With application of special Lewis acids the 6,7-dihalogen-substituted products are formed in relatively high yields (6,7-difluoro-1-ethyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (3a): 71percent; 7-chloro-6-fluoro-1-ethyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (3b): 60percent) without impurities of the corresponding 5,6-dihalogen substituted isomers.Anhydrides (5) of 4-oxo-1,4-dihydro-quinolone-3-carboxylic acids with dibromo- and difluoro-boric acid were synthesized and shown to facilitate the aromatic nucleophilic substitution.The kinetics of two reactions (5a -> 6 and 3b -> 7) were determined and relative reaction rates established.

Process for the preparation of quinoline carboxylic acids

The invention relates to a new process for the preparation of compounds of the Formula I STR1 (wherein R stands for hydrogen or methyl) and pharmaceutically acceptable salts thereof which comprises reacting a compound of the Formula V STR2 (wherein R1 and R2 stand for an aliphatic acyloxy group comprising 2-6 carbon atoms and optionally substituted by halogen; or for an aromatic acyloxy group comprising 7-11 carbon atoms) with an amine of the Formula VI STR3 (wherein R has the same meaning as stated above) or a salt thereof and subjecting the compound of the Formula VII STR4 thus obtained (wherein R, R1 and R2 are as stated above) to hydrolysis after or without isolation and if desired converting the compound of the Formula I thus obtained into a salt thereof or setting free the same from its salt. The compounds of the Formula I are known antibacterial agents. The advantage of the process of the present invention is that it makes the desired compounds of the Formula I available in a simple manner, with high yields and in a short reaction time.

Process for preparing piperazinyl quinolone derivatives

A novel process for preparing piperazinyl quinolone derivatives of the formula (I) is disclosed. The process comprises reacting dihaloquinolones with piperazine derivatives and tetraalkyl ammonium halides in the presence of a polar solvent such as acetonitrile, dimethylformamide, pyridine, sulfolane and dimethyl sulfoxide. STR1

Process for the preparation of quinoline carboxylic acid derivatives

Process for the preparation of useful antimicorbial agents, 1-substituted-6-fluoro-7-(1-piperazinyl or 4-substituted-1-piperazinyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acids having the chemical structure [IV], STR1 wherein R1 is ethyl or vinyl group, and R4 is STR2 (R3 is hydrogen atom or lower alkyl group).