“K-Region” Imines of Some Carcinogenic Aromatic Hydrocarbons

A general synthesis of unsubstituted K-region arene imines from the corresponding arene oxides is described. Reaction of sodium azide with oxiranes gave mixtures of trans azido alcohols, which upon treatment with tri-n-butylphosphine yielded the expected arene imines. By this method the K-imines of benz[o]anthracene, 7-methlbenz[o]anthracene, dibenz[a, h]anthracene, and benzo[o]pyrene were prepared, and means were provided to examine the hypothesis that imines may serve as activated carcinogenic intermediates. The azido alcohols of 7, 12-dimethylbenz[a]anthracene 5, 6-oxide and of benzo[c]phenanthrene 5, 6-oxide reacted with triisopropylphosphine to give isolable Staudinger adducts which, however, could not be converted into cyclic imines.