Synthesis of Isoquinoline-Fused Quinazolinones through Ag(I)-Catalyzed Cascade Annulation of 2-Aminobenzamides and 2-Alkynylbenzaldehydes.

A new route for the expedient synthesis of a specific regioisomer of isoquinoline-fused quinazolinones is reported. Silver(I)-catalyzed cascade cyclization of 2-aminobenzamides and 2-alkynylbenzaldehydes followed by in situ oxidation gives 12-butyl- or 12-aryl-6Hisoquinolino[ 2,1-a]quinazolin-6-ones in 69-91% yields. The structure of the isoquinoline-fused quinazolinone was confirmed by X-ray crystallography analysis. [ABSTRACT FROM AUTHOR]