Template synthesis of a tetraaza macrocycle which involves benzaldehyde rather than formaldehyde as a building block. Isolation and structure determination of the open-chain Schiff base intermediate complex

A scheme for the one-pot synthesis of tetraaza macrocycles using benzaldehyde as the building block has been proposed. The scheme involves the Schiff base condensation of the metal-fee open-chain tetramine with benzaldehyde, formation of the Cu(II) complex and nucleophilic attack by the deprotonated nitroethane fragment to form the macrocyclic fragment. The Schiff base CuII complex and the CuII macrocyclic complex have been isolated in the crystalline form and their molecular structures were determined.