In the Conrad-Limpach reaction, 3-phenanthrylamine undergoes cyclisation at position 4 in accordance with Marckwald's rule, but in the Ullmann-Fetvadjian condensation with β-naphthol and paraformaldehyde, and in the Bernthsen cyclisation of N-(β-naphthyl)-3-phenanthrylamine, the cyclisation at position 2 predominates.