Some reactions with quinoxaline-2,3-dicarboxylic acid anhydride. Synthesis of quinazolinoquinoxalines and quinazolino[2,3:6,1]pyridazino[4,5-b]quinoxalines

Many derivatives of quinazolinoquinoxalincs and quinazolino[2,3:6,1]pyridazino[4,5-b]quinoxaline have been prepared starting from qninoxaline-2,3-dicarboxylic acid anhydride.