Preparation of large macrocyclic tetra‐amines consisting of a methylene backbone and a cyclophane type skeleton

Efficient synthetic routes to 1,10,19,28‐tetraazacyclohexatriacontane, a 36‐membered ring compound with a methylene backbone, and bis(N,N‐octamethylene‐4,4′‐diaminodiphenylmethane), a 38‐membered tetra‐amine with a cyclophane skeleton, have been developed via reduction of tetralactam and via a double condensation reaction, respectively. Overall yields are 51% with 5 steps for the former, and 46% with 6 steps for the latter, while the corresponding 2 + 2 cyclization gave the cyclic compounds in poor yields, 9% and 4%, respectively, for the 36‐membered tetra‐aza ring and for the 38‐membered cyclophane derivative.