The reaction of 2-aminobenzamide with N-substituted pyrrole-2-carboxaldehyde in the presence of Sc(OTf)₃ afforded a tetracyclic structure consisting of dihydroquinazolin-4-one and 1,2-dihydropyrrolo[1,2-a]pyrazine via regioselective double cyclodehydrations where two heterocycles (quinazolinone and pyrazine) were sequentially constructed through formation of three C-N bonds.