AN ALTERNATIVE SYNTHESIS OF TEMAFLOXACIN, A POTENT ANTIBACTERIAL AGENT

An alternative synthesis of (+/-)-7-(3-methylpiperazin-1-yl)-6-fluoro-1-(2,4-difluorophenyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid hydrochloride 4, a potent antibacterial agent, was developed. The method was characterized by regiospecific displacement of the 4-fluoro of the 2,4,5-trifluoroacetophenone by 2-methylpiperazine to produce the key intermediate, 2,5-difluoro-4-(3-methylpiperazin-1-yl)acetophenone 12, which was subsequently converted to 4 via an intramolecular nucleophilic displacement cyclization reaction.