Alumina-supported synthesis of antibacterial quinolines using microwaves.

7-(5'-Alkyl-1',3',4'-thiadiazol/oxadiazol-2'-ylthio)-6 -fluoro-2,4-dimethylquinolines and 3-formyl-2-(2'-hydroxy- 1',4'-naphthoquinon-3'-yl)-4-methyl/6-methyl/7-quinolines have been synthesised by the reaction of 5-alkyl-1,3,4-thiadiazol/oxadiazol-2-thiols with 7-chloro-6-fluoro-2,4-dimethylquinoline and by the reaction of 2-hydroxy-1,4-naphthoquinone with 2-chloro-3-formyl-4-methyl/6-methyl/7-methyl/8-methylquinolines respectively on basic alumina using microwaves, the reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating. The compounds were tested for their in vitro antibacterial activity. All compounds showed promising antibacterial activity. The best activity was observed by compounds 3a and 3f.