The Cyclization of Nitriles by Halogen Acids. A New Synthesis of Substituted 3H-Azepines

The treatment of 2-cyanomethyl-1-cyanomethylenecycloalkanes (XV) with hydrogen bromide in anhydrous media leads to 2-ammo-4-bromo-1H-cycIoalk[d]azepines (XVI). This method, which is general in nature, represents a one-step synthesis of a type of functionally substituted azepine ring which has not been available previously. A preliminary investigation of the chemistry of one of these compounds, 2-amino-4-bromo-6, 7, 8, 9-tetrahydro-1H-3-benzazepine, has been made. Attempts to debrominate it reductively have failed so far.