Synthesis of 9-alkyl-6-amino[1,2,4]triazolo[3,4-c]-5-azaquinoxalines. Mild and effective SNAr amination of highly electron-poor heterocycles

The synthesis and characterization of five different 9-alkyl-6-amino[1,2,3]triazolo[3,4-c]-5-azaquinoxalines is described. Due to the notable electrophilic character of the C-6 position of the [1,2,4]triazolo[3,4-c]-5-azaquinoxaline tricyclic system, SNAr amination was achieved simply by reacting the corresponding 6-chloro derivative with ammonia-saturated acetonitrile (a non-nucleophilic polar solvent) in a sealed reaction vessel, using microwave-mediated or conventional heating.