Synthesis of novel bifunctional Schiff-base ligands derived from condensation of 1-(p-nitrobenzyl)ethylenediamine and 2-(p-nitrobenzyl)-3-monooxo-1,4,7-triazaheptane with salicylaldehyde

Two potentially tetradentate (N2O2) and pentadentate (N3O3) bifunctional Schiff-base ligands, N,N'-bis(2-hydroxybenzyl)-1-(p-aminobenzyl) ethylenediamine (7) and N, N'-bis(2-hydroxybenzyl)-2-(p-aminobenzyl)-3-monooxo-1,4,7-triazaheptane (5') have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). They are derived from the condensation reactions of the C-functionalized diamines 1-(p-nitrobenzyl) ethylenediamine and 2-(p-nitrobenzyl)-3-monooxo-1,4,7-triazaheptane with 2.1 equiv. of salicylaldehyde. The first complexation trials with Tc-99m are reported.