Title: Difloxacin
CAS Registry Number: 98106-17-3
CAS Name: 6-Fluoro-1-(4-fluorophenyl)-1,4-dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid
Molecular Formula: C21H19F2N3O3
Molecular Weight: 399.39
Percent Composition: C 63.15%, H 4.80%, F 9.51%, N 10.52%, O 12.02%
Literature References: Fluoroquinolone antibacterial structurally related to norfloxacin, q.v. Prepn: D. T. W. Chu, EP 131839; idem, US 4730000 (1985, 1988 both to Abbott); D. T. W. Chu et al., J. Med. Chem. 28, 1558 (1985); H. Narita et al., JP Kokai 85 237069 (1985 to Toyama). Antibacterial spectrum in vitro: J. M. Stamm et al., Antimicrob. Agents Chemother. 29, 193 (1986); in vivo: P. B. Fernandes et al., ibid. 201. Activity vs anaerobic bacteria: eidem, J. Antimicrob. Chemother. 18, 693 (1986). HPLC determn in biological fluids: G. R. Granneman, L. T. Sennello, J. Chromatogr. 413, 199 (1987). Pharmacokinetics in humans: G. R. Granneman et al., Antimicrob. Agents Chemother. 30, 689 (1986).
Derivative Type: Monohydrochloride
CAS Registry Number: 91296-86-5
Manufacturers' Codes: Abbott 56619; A-56619
Trademarks: Dicural (Fort Dodge)
Molecular Formula: C21H19F2N3O3.HCl
Molecular Weight: 435.85
Percent Composition: C 57.87%, H 4.63%, F 8.72%, N 9.64%, O 11.01%, Cl 8.13%
Properties: Crystals, mp >275°.
Melting point: mp >275°
Therap-Cat-Vet: Antibacterial.
Diflubenzuron Diflucortolone Diflufenican Diflufenzopyr Difluoroiodotoluene

Systematic (IUPAC) name
6-fluoro-1-(4-fluorophenyl)-7-(4-methylpiperazin-1-yl)- 4-oxoquinoline-3-carboxylic acid
Clinical data
AHFS/Drugs.com International Drug Names
Legal status  ?
Routes Oral
CAS number 98106-17-3 YesY
91296-86-5 (HCl)
ATCvet code QJ01MA94
PubChem CID 56206
ChemSpider 50725 N
KEGG D07828 YesY
Chemical data
Formula C21H19F2N3O3 
Mol. mass 399.39 g/mol
 N (what is this?)  (verify)

Difloxacin (INN) is a fluoroquinolone antibiotic used in veterinary medicine.[1] Although a broad-spectrum antimicrobial, its efficacy is not as good as enrofloxacin or pradofloxacin.[2]