Synthesis and biological evaluation of N-antipyrine-4-substituted amino-3-chloromaleimide derivatives.

This paper describes the synthesis of new cyclic imides obtained by reaction with N-antipyrine-3,4-dichloromaleimides and different aromatic amines. The analgesic activity of the synthesized compounds was initially investigated against the writhing test in mice, followed by analysis of the most promising compounds in this model and in the formalin-induced model. The results indicate that the compounds containing the electron-withdrawing substituents in the para position of the substitute ring exerted more potent analgesic activity in mice, being much more potent than the prototype N-antipyrine-3,4-dichloromaleimide and some reference drugs.

4'-Acetamidochalcone derivatives as potential antinociceptive agents.

Nine acetamidochalcones were synthesized and evaluated as antinociceptive agents using the mice writhing test. Given intraperitoneally all the compounds were more effective than the two reference analgesic drugs (acetylsalicylic acid and acetaminophen) used for comparison. N-{4-[(2E)-3-(4-nitrophenyl)prop-2-enoyl]phenyl}acetamide (6) was the most effective compound and was therefore selected for more detailed studies.