Effective coupling of Re/Tc-MAG₃ complexes with amines and nucleobases in aprotic solvents.

The coupling of Re- and ^99mTc-MAG₃ complexes with amines and nucleobases was carried out with good yields using O-(benzotriazol-1-yl-)N,N,N',N'-tetramethyl-
uronium-tetrafluoroborate (TBTU), and base in polar aprotic solvents (NMP, DMF, DMSO). The one step reaction followed by simple gel chromatography makes the method well appropriate for preparations at the low no-carrier-added level of technetium-99m.