Synthesis and antibacterial activity of some 7‐substituted 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acids: Ethers, secondary amines and sulfides as c‐7 substituents

A series of 7‐substituted 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acids were prepared from 1‐ethyl‐6,7‐difluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid 8 . Those derivatives reported contain acyclic and heterocyclic substituents linked to the quinolone C‐7 position via O, NH or S. The in vitro antibacterial data of some of these derivatives against 4 Gram positive and 4 Gram negative organisms are reported.