Synthesis of Radioiodinated Carbocyclic Cytosine Analogues

Abstract

The synthesis of carbocyclic analogues of normal nucleosides has grown exclusively since they have shown potential antiviral and antitumor activities. Radiolabeled cis-1[4-(hydroxy-methyl)-cyclopent-2-enyl]-5-[I-124]-iodocytosine (carbocyclic d4IC) and cis-1[4-(hydroxy-methyl)-cyclopent-2-enyl]-5-(2-[I-124]iodovinyl)cytosine (carbocyclic d4IVC) were synthesized. The synthetic route employed Pd(0)-catalyzed coupling reaction together with organotin and exchange reaction for radioiodination as key reactions. Carbocyclic [I-124]d4IC gave more than 75% radiochemical yield with greater than 95% radiochemical purity. Carbocyclic [I-124]d4IVC gave more than 80% radiochemical yield with greater than 95% radiochemical purity.