Electrochemical radiofluorination using a split-bipolar electrode

• Electrochemical radiofluorination (ECF) is achieved with split bipolar electrodes. • Radiochemical conversion of up to 70 % for methyl (methylthio)acetate. • A m of 28–43 GBq/μmol is achieved with starting activity of 2.5–3.3 GBq. • A m obtained in this work is five times higher than previous reports using ECF. Electrochemical (radio)fluorination (ECF) is a versatile approach for nucleophilic radiofluorination of electron-rich compounds such as thioether derivatives. However, ECF generally requires high concentrations of supporting salts, which leads to low molar activity ( A m ) of the final product due to undesired contamination with [ 19 F]F – ions. Here, we demonstrate the first example of radiofluorination using a split bipolar electrode (s-BPE) platform with low concentration of supporting salt. Under optimal reaction conditions, the ECF of methyl (methylthio)acetate (MMTA) using s-BPEs provided [ 18 F]F-MMTA with radiochemical conversion of up to 70 % and high molar activities (28–43 GBq/μmol; 0.74–1.1 Ci/μmol), with approximately 5 mM of tetrabutylammonium perchlorate as supporting electrolyte.