A simple method to generate [18F]triflyl fluoride for 18F radiosynthesis

A simple, continuous-flow solid-phase radiosynthesis method has been developed for the generation of [F-18]triflyl fluoride as a source of [F-18]fluoride for the preparation of F-18 labeled radiopharmaceuticals without the need for an azeotropic drying step. After [F-18]fluoride was trapped and dried on an anion-exchange resin cartridge, gaseous [F-18]triflyl fluoride was generated directly by eluting the cartridge with a solution of PhN(OTf)(2), followed by isolation from the eluted reaction mixture via an empty cartridge and conversion to [F-18]fluoride in a basic solution for radiofluorination. A peristaltic pump was used to maintain flow through the above stages, eventually providing reaction-ready [F-18]fluoride in over 90% radiochemical yield in less than 10 min. Up to 0.057 mu g non-radioactive fluoride was introduced from the reagents and components used during the above processes. Several radiolabeling reactions were carried out using the [F-18]fluoride generated in this manner, affording the labeled products in good to high radiochemical yields. This method should have great potential for the safe and convenient preparation of F-18 labeled radiopharmaceuticals. (C) 2021 Elsevier Ltd. All rights reserved.