Synthesis of Double Benzimidazole-Fused Quinazolines and Pyrimidines Catalyzed by Recyclable Magnetic Cu-MOF-74

2-(2-Bromoaryl)- and 2-(2-bromovinyl)benzimidazoles are combined and cyclized with benzimidazoles using a catalytic amount of magnetic Cu-MOF-74 (Fe₃O₄@SiO₂@Cu-MOF-74) and a base under O₂ atmosphere, yielding the corresponding double benzimidazole-fused quinazolines and pyrimidines. The catalyst can be recovered using a magnetic bar and reused multiple times without significant loss of catalytic activity. The reaction mechanism likely involves the initial formation of a C−N coupled intermediate through nucleophilic aromatic substitution, followed by oxidative cyclization.