Résumé : Cross-ring coupling between aromatic protons has been observed in substituted phenanthrene and benzo[c]phenanthrene derivatives. It is suggested that the well resolved cross-ring coupling of H1 in 4-methoxybenzo[c]phenanthrene and 4-aminobenzo[c]phenanthrene involves two protons (H5 and H8), one of which (H8) is located in a non-adjacent ring (Fig. 2). © 1965.