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-6H-isoquinolino[2,1-a]quinazolin-6-ones in 69–91% yields. The structure of the isoquinoline-fused quinazolinone was confirmed by X-ray crystallography analysis.
Key words
isoquinoline - quinazolinone - regioisomer - silver catalyst - cascade annulation