Direct solid-phase synthesis of quinoxaline-containing peptides

The solid-phase synthesis of a series of model dipeptides containing various 3-(quinoxalin-6-yl)alanine analogues is described. The method involves formation of a quinoxaline heterocycle by condensation between an α-dicarbonyl compound and a β-(3,4-diaminophenyl)alanine residue, immobilized on a solid support.