The synthesis of benzoquinolines and benzoquinolinones via Friedländer-type condensation of aminonaphthalene carbaldehydes with (1) primary or secondary alcohols mediated by urea/KOH or with (2) diketones or b-ketoesters is described. The behavior of naphthalene derivatives in the Friedländer annulation, resulted in the formation of Friedländer or non-Friedländer products, is also presented.
Graphical abstract