RADIOPHARMACEUTICAL DESIGN USING NOVEL RE-188 IMIDO COMPLEXES

Several efficient new methods for synthesizing rhenium compounds conta ining a multiply bonded imido linkage (Re=N-R) between the metal and o rganic compounds for radiopharmaceutical applications are reported. Th e imido linkage is stable and compatible with typical organic function al groups, and offers distinct structural and synthetic advantages ove r other types of linkages commonly used in radiopharmaceutical design. Syntheses of representative peptide and steroid compounds from hydraz ine and phosphinimine imido precursors are described, and the preparat ion of a Re-188-imido complex is discussed. A promising new Re-188-rad iolabeling strategy for directly synthesizing rhenium imido radiopharm aceuticals, targeted for low-capacity receptor sites relevant for canc er therapy and based on solid supported imido precursors, is presented .