Synthesis and ¹⁸F-radiolabeling of thymidine AMBF₃ conjugates

In pursuit of ¹⁸F-labeled nucleosides for positron emission tomography (PET) imaging, we report on the chemical and radiochemical synthesis of two thymidine (dT) analogs, dT-C⁵-AMBF₃ and dT-N³-AMBF₃, that are radiofluorinated by isotope exchange (IEX) and studied as PET imaging agents in mice with tumor xenografts. dT-C⁵-AMBF₃ shows preferential, and tumor-specific, uptake over dT-N³-AMBF₃. This work provides a new synthetic method in order to access new nucleoside tracers for PET imaging.