Synthesis, crystal structure and calculation of oxides of 2-methylamino-3-methyl quinoxaline

Monoxide and dioxide of animo quinoxaline were synthesized and characterized by 1H NMR, 13C NMR and HRMS. The result shows that monoxide is main product. 1H NMR analysis, quantum calculation and crystal structure all indicate that the monoxide is 4-oxide structure but not 1-oxide structure. The subsequent discussions of electronic effect and steric effect of 1-oxide and 4-oxide support the conclusion that 4-oxide is dominant product, which is consistent with 1H NMR analysis and crystal structure. At last, the calculated structure is in good agreement with the crystal structure in this paper, which indicates that the calculation result in this paper is credible.