Résumé : This paper describes the synthesis of the following compounds: tribenzo [a,c,g] fluorene (I → IV), tetrabenzo [a,c,g,i] fluorene (VI → X), 9‐(1‐naph‐tyl) phenanthrene and 9‐(2‐naphtyl) phenanthrene. The bromination of 9‐amino‐ and 9‐acetylaminophenanthrene, using either bromine or N‐bromosuccinimide, is also reported. U. V. spectra of the end products and of a few intermediates have been recorded (Fig. I, II, III and IV). Copyright © 1960 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim