Lysine conjugates for the labelling of peptides with technetium-99m and rhenium

A novel method of preparing Tc-99m labelled peptides, through the incorporation of a lysine analogue containing a metal chelation centre, is proposed. alpha-CBZ-Lysine has been conjugated to an N2S2 bifunctional chelator yielding 1, which has been chelated with both rhenium and technetium-99m and can yield a single isomer product. A Fmoc protected lysine analogue, has been prepared, and is ready for incorporation into a peptide by standard peptide synthetic methods, with the potential of the forming a single isomer Tc-99m labelled peptide.