Regioselective double dehydrative cyclization route to construct polyheterocyclic skeletons consisting of 2,3-dihydroquinazolin-4(1H)-ones and 1,2-dihydropyrrolo[1,2-a]pyrazines

Abstract

The Sc(OTf)₃-catalyzed reaction of 2-aminobenzamide with N-substituted pyrrole-2-carboxaldehyde proceeded well to give a tetracyclic skeleton consisting of dihydroquinazolin-4-one and 1,2-dihydropyrrolo[1,2-a]pyrazine via regioselective double cyclodehydrations where two heterocyclic rings (quinazolinone and pyrazine) were sequentially constructed through the formation of three C–N bonds.