The chemistry of polycyclic arene imines. II. Photochemistry of phenanthrene 9,10‐imine and of its N‐butyl derivative

The uv irradiation of phenanthrene 9, 10‐imine has been shown to give 9H‐tetrabenzo[a, c, g, i]carbazole as the major photo‐product both in argon purged acetone and in dichloromethane. Phenanthrazine, N‐9‐phenanthrenyl‐9‐phenanthrenamine and phenanthrene were formed in smaller quantities. 9‐Phenanthrenamine was found to be a minor by‐product. N‐Butylphenanthrene 9, 10‐imine yielded under similar conditions phenanthrene and N‐butyl‐9‐phenanthrenamine as the only isolable polycyclic compounds. In the presence of air the substituted imine gave mainly 2‐propylphenanthro[9, 10‐d]oxazole.