Non-template synthesis of ‘N4’ di- and tetra-amide macrocylic ligands with variable ring sizes

Nine new macrocyclic ligands containing two- or four-amide groups have been prepared by the cyclization reaction of three different diamines with acid chlorides (oxalyl dichloride or malonyl dichloride), diesters (diethyl oxalate or diethyl malonate) or 1,2-dichloroethane. The macrocycles prepared are four tetraaza-14-crown-4, four tetraaza-15-crown-4 and one tetraaza-16-crown-4. All the macrocyclic ligands were characterized by elemental analysis and, IR, UV, NMR and mass spectral investigations.