4-Hydroxycoumarin is shown to undergo a novel reaction with primary arylamines and paraformaldehyde to give chromenoquinolines, which are analogues of the carcinogenic benzacridines and dibenzacridines. Isochromenoindoles, analogous to mono- and di-benzocarbazoles, were prepared by indolisation of aryl- and quinolylhydrazones of isochroman-1,4-dione. The electron-impact fragmentation of these compounds is discussed.