Synthesis of new 4-(E)-alkenylpyrrolo[1,2-a]quinoxalines as antileishmanial agents by Suzuki-Miyaura cross-coupling reactions

Abstract

A series of new 4-(E)-alkenylpyrrolo[1,2-a]quinoxaline derivatives, structural analogues of alkaloid chimanine B, was synthesized in good yields using efficient palladium(0)-catalyzed Suzuki-Miyaura cross-coupling reactions. These new compounds were tested for in vitro antiparasitic activity upon Leishmania amazonensis and Leishmania infantum strains. Biological results showed activity against the promastigote forms of L. amazonensis and L. infantum with IC₅₀ ranging from 0.5 to 7 μM. From a Structure-Activity Relationships point of view, these pharmacological results mainly enlightened the importance of the 4-lateral C₆, C₇ or C₈ α-unsaturated trans-alkenyl chain of unsubstituted pyrrolo[1,2-a]quinoxaline moiety.

Keywords::

• 4-Alkenylpyrrolo[1,2-a]quinoxaline
• antileishmanial agents
• leishmania amazonensis
• leishmania infantum
• suzuki reaction