Abstract: Phenylmalonyl heterocycles such as 3-phenyl-4-hydroxy-2-quinolones or 3-phenyl-4-hydroxycoumarins cyclize with high boiling esters such as diphenyl carbonate or arylmalonates to give isocoumarines. Dehydrogenation of 3-phenyl-4-hydroxy-2-quinolones or 3-phenyl-4-hydroxycoumarins with palladium on charcoal gives coumestan- or azacoumestanderivates.