Site Selectivity in Reactions of Hydrazonoyl Halides With 2-Amino-3-quinoxalinethiol: A New General Access to Functionalized 4H-1,3,4-Thiadiazino-[5,6-b]quinoxalines

The synthesis of various 2,4-disubstituted 4H-1,3,4-thiadiazino-[5,6-b]quinoxalines via reaction of hydrazonoyl halides with 2-amino-3-quinoxalinethiol in ethanol in the presence of sodium ethoxide is described. The structures of the reaction products were elucidated by chemical evidence and by their IR, ¹ H, ¹³ C-NMR, and MS spectra. The mechanism of the formation of the products is also discussed.

Keywords:

• Heterocycles
• hydrazonoyl halides
• site selectivity
• thiadiazinoquinoxalines