Copper‐Catalyzed Sequential Azide‐Alkyne Cycloaddition (CuAAc) and Ullmann Coupling: A Tandem One‐Pot Synthesis of Quinazolino[3,2‐ <i>c</i> ][1,2,3] Triazolo[1,5‐ <i>a</i> ]‐Quinazolin‐14‐One

An efficient copper‐catalyzed tandem strategy for the construction of triazole‐fused polycyclic quinazolinone frameworks has been developed. This methodology is accomplished through a multicomponent protocol involving 2‐bromophenyl quinazolinones, sodium azide, and terminal alkynes and proceeds via copper‐catalyzed azide–alkyne cycloaddition (CuAAC), Ullmann‐type C—N coupling, and intramolecular C—N bond formation, delivering quinazolino[3,2‐ c ] [1,2,3] triazolo[1,5‐ a ] quinazolin‐14‐ones in 60%–78% yields. Current protocol provides a concise and valuable route for constructing structurally complex polycyclic N‐heterocycles with potential pharmaceutical relevance.