197520-73-3

Upstream product

• 153775-33-8 2,4-difluoro-5-nitro-benzoic acid 
• 179741-60-7 tert-butyl (5-amino-2,4-difluorophenyl)carbamate 
• 179741-61-8 tert-butyl (2,4-difluoro-5-nitrophenyl)carbamate 
• 112062-51-8 ethyl 2-(2,3-dichloro-4,5-difluorobenzoyl)-acetate 
• 208166-48-7 N-tert-butoxycarbonyl-2,4-difluoro-m-phenylenediamine 
• 101987-86-4 ethyl β-(3-chloro-2,4,5-trifluorophenyl)-β-oxopropionate 
• 109-94-4 formic acid ethyl ester 
• 1583-58-0 2,4-difluoro-benzoic acid 
• 112822-71-6 (Z)-2-(2,3-Dichloro-4,5-difluoro-benzoyl)-3-ethoxy-acrylic acid ethyl ester 
• 221560-09-4 2,4-Difluoro-5-nitrobenzoyl Chloride 

Downstream Products

• 179740-21-7 1-(5-amino-2,4-difluorophenyl)-8-chloro-6,7-difluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 

Relevant academic research and scientific papers

A novel antibacterial 8-chloroquinolone with a distorted orientation of the N1-(5-amino-2,4-difluorophenyl) group

Fluoroquinolones represent a major class of antibacterial agents with great therapeutic potential. In this study, we designed m-aminophenyl groups as novel N-1 substituents of naphthyridones and quinolones. Among newly synthesized compounds, 7-(3-aminoazetidin-1-yl)-1-(5-amino-2,4-difluorophenyl)-8-chloro-6- fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (4) has extremely potent antibacterial activities against Gram (+) as well as Gram (-) bacteria. This compound is significantly more potent than trovafloxacin against clinical isolates: 30 times against Streptococcus pneumoniae and 128 times against methicillin resistant Staphylococcus aureus. The structure-activity relationship (SAR) study revealed that a limited combination of 1-(5-amino-2,4-difluorophenyl) group, 7-(azetidin-1-yl) group, and 8-Cl atom (or Br atom or Me group) gave potent antibacterial activity. An X-ray crystallographic study of a 7-(3-ethylaminoazetidin-1-yl)-8-chloro derivative demonstrated that the N-1 aromatic group was remarkably distorted out of the core quinolone plane by steric repulsion between the C-8 Cl atom and the N-1 substituent. Furthermore, a molecular modeling study of 4 and its analogues demonstrated that a highly distorted orientation was induced by a steric hindrance of the C-8 substituent, such as Cl, Br, or a methyl group. Thus, their highly strained conformation should be a key factor for the potent antibacterial activity.

Phenylenediamines and process for preparing the same

Phenylenediamines represented by general formula (1): STR1 wherein R represents an alkyl group or an optionally substituted aralkyl group, X1 represents a hydrogen atom or a halogen atom, and X2 represents a halogen atom; salts thereof, and a process for preparing the same. The compounds are useful as intermediates for synthesis of pyridonecarboxylic acid derivatives useful as antibacterial agents.