Synthesis and evaluation of analgesic, anti-inflammatory and antimicrobial activities of 6-acyl-3-piperazinomethyl-2-benzoxazolinones

In this study, 16 new 6-difluorobenzoyl-3-piperazinomethyl-2-benzoxazolinones were synthesized by Mannich reaction. Their chemical structures were proven by IR, ¹H-NMR and elemental analysis. The compounds were screened for their analgesic and anti-inflammatory activities. A modified Koster test, using acetylsalicylic acid (ASA, CAS 50-78-2) as the reference drug, was used to assess analgesic activity. The anti-inflammatory activity was evaluated by the carrageenan induced hind-paw oedema test. The analgesic activities of all compounds were higher than their anti-inflammatory activities and therefore the prominent analgesic actions of the compounds are thought to be due to a central effect. The microbiological effects of the compounds were evaluated in vitro against various pathogenic fungi and bacteria using the microdilution method. Most of the compounds were found to be inactive against bacteria and fungi. One of the compounds (3l) possessed considerable analgesic activity as well as moderate antibacterial activity against S. aureus. Another compound (3m) showed analgesic and anti-fungal activities comparable to those of ASA and fluconazole (CAS 86386-73-4), respectively.