Synthesis and biological evaluation of amide derivatives of diflunisal as potential anti-inflammatory agents

To improve the medicinal activity, the structure of diflunisal has been modified. Twenty-one amide derivatives of diflunisal were synthesized starting from diflunisal in three steps with total yields from 72% to 89%. All compounds were identified by ¹H NMR, MS, and elemental analysis. The anti-inflammatory and analgesic activities for 19 compounds were evaluated. It was found that 5m possesses an excellent anti-inflammatory activity and a good analgesic activity, maybe a potential anti-inflammatory agent.