The 1-N-(4-aminobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine ligand (Sarar) was the first bi-functional hexa-aza bicyclic cage used for 64Cu radiolabelling of proteins for positron emission tomography (PET). Since its first application in molecular imaging, there has been increasing interest to develop other hexa-aza cage ligands with functional groups for reaction with different active groups on proteins, peptides and nanomaterials. Here we present the synthesis of over 15 new substituted hexa-aza cages via reductive amination of the substituted aldehyde with the Cu(II) diamsar (3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine) and the new method using metal free diamsar. The latter affords the synthesis of a range of new ligands not previously possible. Hexa-aza cages incorporating functional groups such as isothiocyanate, nitro-, maleimide, hydroxy, halogens, ortho- and meta- amino and alkyl groups have been isolated. Their metal complexation behaviour with a range of transition metal radioisotopes (i.e.64Cu, 57Co, 65Zn, 109Cd) has also been investigated over a range of pH and metal/ligand concentrations.

Next generation of hexa-aza bicyclic cages: Probes for molecular imaging

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.