Synthesis and antimicrobial activity of cyclopentyl-substituted halogenophenoxyacetic acids and their amides

A series of cyclopentylhalogenoanisoles have been synthesized by alkylation of o- and p-chloro- and fluoroanisoles with cyclopentene in the presence of BF₃·H₃PO₄. The compositions and structures of the products were studied by GC, IR, and NMR spectroscopy. Demethylation of the cyclopentylhalogenoanisoles yielded cyclopentylhalogenophenols, which were reacted with chloroacetic acid and chloroacetamide to obtain cyclopentyl-substituted chloro- and fluorophenoxyacetic acids and their amides. Results of studying the antimicrobial activity of the synthesized acids and their amides against S. viridans, S. flexneri, P.aeruginosa, B. antracoides, K. rhinoscleromatis, and C. albicans are presented. All substances show moderate activity against the test microbes (minimum bacteriostatic concentrations from 31.25 to 125 μg/mL). Introduction of a cyclopentyl substituent into the structure of 2-chlorophenoxyacetic acid improves the activity against S. viridans, P. aeruginosa, and K. rhinoscleromatis. These data can be used to study the relationship between the structures and antimicrobial activity.