Аннотация:The use of nuclear-chemical synthesis, based on the generation of free nucleogenic phenyl cations, allowed for the direct phenylation of the nitrogen atom in 1,4-diazines. The presence of two methyl substituents in the quinoxaline substrate leads to a marked increase of diazine salt radiochemical yield. On the basis of quantum-chemical calculations the possibility of synthesizing 2,3-dimethyl-1,4-di-phenylquinoxalinium dication is proposed.