The formation and decomposition of 1,4,8,11 -tetra -azacyclotetradeca-4,11-dienes

Abstract

When ethylenediamine reacts with benzylideneacetone the final product isolated is a tetra-azacyclotetradecadiene (4) but the reaction path is complex and proceeds via an equilibrium mixture containing two macrocycles, a tetrahydrodiazepine, and a mono-condensation product. If the macrocycle (4) is heated, or left in solution at room temperature, the same equilibrium mixture is generated. Removal of ethylenediamine from this mixture promptes formation of a bisenimine which on addition of ethylenediamine slowly regenerates the equilibrium mixture. The macrocycle (4) is cleaved by hydroxylamine to give an oxime. Some new tetra-azacyclotetradecadienes hale been prepared. The reaction between neat ethylenediamine and enones, previously reported to provide tetrahydrodiazepines, gives either macrocycles or bisoxoenamines as the isolated products.