Design and synthesis of novel semi-rigid multidentate ligands, withamido or amino donor groups: versatile compounds for the preparationof rhenium and technetium radiopharmaceuticals

摘要

Synthetic pathways to a range of novel semi-rigid multidentate ligands, with amido or amino donorrngroups, designed to coordinate to rhenium and technetium have been developed. Using formyl substituted anilines asrnthe compounds containing the active proton center, glycine as the amine, and paraformaldehyde as the aldehydernperformed the reaction. The method was successful and was very promising to design ligands of various molecularrnstructures. These ligands were capable to coordinate to rhenium metal ions in aqueous solutions through ligandrnexchange with the complex ReOCl3(PPh3)2 to give new rhenium complex ReOCl3L. These compounds werernidentified spectrophotometrically, so as their complexes with rhenium by using U.V–vis and infrared absorptionrnspectrophotometry, as well as the other classical techniques such as microanalysis and molecular weightrndetermination by depression of freezing point. It was found that they can be labeled with 99mTc pertechnetate, andrntheir radioactive purity recommends their use in radiopharmaceuticals.