Synthesis, anticonvulsant, and anti-inflammatory activities of some new benzofuran-based heterocycles

Treatment of 2-bromoacetylbenzofuran (2) with pyridine afforded its corresponding pyridinium bromide 3. The latter salt reacted with some activated alkenes and acetylenes to give the corresponding indolizine derivatives. Treatment of the salt 3 with benzylidenemalononitriles 9 afforded polysubstituted aniline derivatives, however with arylidenecyanothioacetamides 15 it gave the corresponding 4,5-dihydrothiophenes. Bromide 3 also coupled with p-chlorobenzenediazonium salt followed by ammonium acetate to give the corresponding 1,2,4,5-tetrazine derivative. The biological activity of the newly synthesized compounds was examined and some of them were found to possess anticonvulsant and anti-inflammatory activities.