An Alternative Approach to the Synthesis of New Pyrimido[5′,4′:5,6][1,4] Thiazino[2,3-B]Quinoxaline Derivatives

Abstract

An alternative approach to the synthesis of a series of new pyrimido[5′,4′:5,6][1,4]thiazino[2,3-b]quinoxaline derivatives is described. Reaction of 5-bromo-2,4-dichloro-6-methylpyrimidine and 3-aminoquinoxaline-2-thiol leads to the key intermediate 3-[(5-bromo-2-chloro-6-methylpyrimidin-4-yl)thio]quinoxalin-2-amine. This intermediate can be transformed into the title ring systems by subsequent treatment either with secondary amines followed by intramolecular cyclisation or initial intramolecular cyclisation with subsequent reaction with secondary amines.

Synthesis of New Pyrimido[5′,4′:5,6][1,4]thiazino[2,3‐b]quinoxaline Derivatives in One Step

“…Furthermore, quinoxaline containing heterocycles have also significant applications in the field of industrial and agricultural and have been applied as dyes, electroluminescent materials, and insecticides . Recently, improved methods have also been reported for the synthesis of heterocycles containing the quinoxaline .…”