EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY, cilt.67, ss.230-242, 2013 (SCI-Expanded)
Norfloxacin was converted to 7-(4-amino-2-fluorophenyl)piperazin derivative (2) via the formation of nitro compound. The synthesis of the norfloxacin derivatives containing 1,3-thiazole or 1,3-thiazolidin moiety was performed from the reaction of 4-chlorophenacylbromide or ethyl bromoacetate with compounds 4-7 obtained starting from 2. 3-Fluoro-4-[4-(2-methoxyphenyl)piperazin-1-yl]aniline (14), 5-{[4-(2-methoxyphenyl)piperazin-1-yl]methyl}-4-phenyl-4H-1,2,4-triazole-3-thiol (18) and {[4-(2-methoxy phenyl)piperazin-1-yl]methyl)-1,3,4-oxadiazol-2-thiol (19) were obtained starting from 1-(2-methoxyphenyl)piperazine by several steps. The treatment of hydrazide (16) with several aldehydes afforded N'-[(2-hydroxyphenyl)methylen]- (20), N'-[(3-hydroxy-4-methoxy phenyl)methylen]- (21) or N'-[1H-indol-3-ylmethylene]-2-[4-(2-methoxyphenyl)piperazin-1-yl]acetohydrazide (22). Then, compounds 14, 18, 19 and 22 were condensed with 7[4-(chloroacetyl)piperazin-1-yl]-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (3) that was obtained from norfloxacine.