One-pot synthesis of biologically active 1,2,3-trisubstituted pyrrolo[2,3-b]quinoxalines through a palladium-catalyzed reaction with internal alkyne moieties.

Synthesis of 2,3-disubstituted 1-alkylpyrrolo[2,3-b]quinoxalines was accomplished through the reaction of 3-chloroquinoxalin-2-amines with internal alkynes in the presence of Pd(OAc)[Formula: see text], NaOAc, and KOtBu in DMSO. This method afforded desired pyrrolo[2,3-b]quinoxalines in 65-92% reaction yields. The minimum inhibition concentration and minimum bactericidal concentration determinations against Micrococcus luteus and Pseudomonas aeruginosa revealed that some of the synthesized compounds showed the same values compared to tetracycline. These compounds could be used in the future research for the development of new antibiotics.