Synthesis and in vitro anti-inflammatory activity of pyrrolo[1,2-a]pyrazines via Pd-catalyzed intermolecular cyclization reaction

Pyrrolo[1,2-a]pyrazine possessed widely bioactivities due to its particular structure. In this work, three pyrrolo[1,2-a]pyrazines derivatives were synthesized from the 2-bromo-5- methoxypyrazine and propargyl amines or ethers through the Pd-catalyzed intermolecular cycloisomerization strategy. Their structures were characterized by NMR, IR, EI-MS and elemental analysis, and all of them exhibited moderate in vitro anti-inflammatory effects with the inhibitions of 43-59% against IL-6 at 50 μM. The compound 3c revealed relatively good anti-inflammatory activities. The bioactive pyrrolo[1,2-a]pyrazines might be potentially used as anti-inflammatory agents. © (2014) Trans Tech Publications, Switzerland.