Synthesis and Antimicrobial Evaluation of Novel <i>N</i>-Substituted β-Hydroxy Benzimidazole Sulfone Fluoroquinolones by Selective Oxidation Using Ticl<sub>4</sub>-H<sub>2</sub>O<sub>2</sub>
作者:B. Guruswamy、R. Arul
DOI:10.1080/10426507.2012.740702
日期:2013.9.1
The synthesis of N-substituted -hydroxy benzimidazole sulfones containing 8-methoxy fluoroquinolone has been described and they were evaluated for antimicrobial activities. The compounds of N-substituted -hydroxy benzimidazole sulfides (4a-e) and N-substituted -hydroxy benzimidazole sulfones (5a-e) at C-7 of fluoroquinoline exhibited superior activity in vitro. 8-Methoxy fluoroquinolone carboxylic acid (1), reaction with piperizine in acetonitrile in presence of triethylamine under reflux gives 7-piperazinyl-8-methoxyfluoroquinolone (2). The latter is reacted with epichlorohydrine in presence of NaOH in acetone yielded N-substituted epoxide (3), which on treatment with 5-substituted-2-mercaptobenzimidazoles gives N-substituted -hydroxy benzimidazole sulfides (4). Further, 4 on treatment with TiCl4-H2O2 and in DCM yielded the corresponding N-substituted -hydroxy benzimidazole sulfone (5).