A synthesis for preparing a tetraamido-macrocyclic ligand, such as 5,6-Benzo-3,8,11,13-tetraoxo-2,2,9,9-tetramethyl-12,12-diethyl-1,4,7,10-tetraazacyclotridecane, H4, in greatly improved yield and in a commercially viable manner, comprising the steps of dissolving a quantity of a 1,2-bis(2-aminoalkanamido)benzene in a solution comprised of methylene chloride and ethyl acetate to yield a first reaction solution; dissolving a quantity of a malonyl dihalide in an ethyl acetate solution to yield a second reaction solution; adding the first reaction solution and the second reaction solution to a reaction vessel containing a third reaction solution comprised of refluxing ethyl acetate solution and an acid scavenger to form a reaction mixture; and isolating a solid product comprised of the tetraamido-macrocycle directly from the reaction mixture by filtration.