The chemistry of polycyclic arene imine. VI. 1‐[ N,N ‐di‐(2‐propenyl)‐9‐phenanthreneamine‐10‐yl]‐1a,9b‐dihydrophenanthro[9,10‐ b ]azirine an unusual allylation product of phenanthrene 9,10‐imine

Phenanthrene 9,10‐imine (1) was shown to react with allyl bromide and 50% aqueous sodium hydroxide under phase transfer catalysis conditions to give the title compound 3 as the only product. The starting imine 1 is assumed to undergo initially bis alkylation to form an N,N ‐di‐(2‐propenyl)phenanthrene 9,10‐iminium salt (4) which, in turn, is attacked by a deprotonated phenanthrene imine anion (5). The structure of 3 has been determined by a single crystal X‐ray diffraction analysis.