Novel Synthesis of Dihydroquinoxalinylpyridazine Derivatives

Methylquinoxaline derivative 1 undergoes bromination to give bromomethyl quinoxaline 2 , which could be transferred to cyanomethyl quinoxaline 3 . The latter compound 3 readily coupled with arene diazonium salts to give hydrazone derivatives 5a‐c . Compounds 5a,b reacted with active methylene reagents to give the target ring system, quinoxalinylpyridazine derivatives 8a‐c . Compound 1 reacted with DMFDMA to give the enamine derivative 9 , which coupled with arene diazonium salts to give the aldehydic hydrazone derivatives 10a‐c . Compound 10 reacted with active methylene compounds to give quinoxalinylpyridazine derivatives. UV characterization of some of the prepared compounds was reported.