Investigations to the synthesis of n.c.a. [18F]FClO3 as electrophilic fluorinating agent

An approach to synthesize the electrophilic fluorinating agent no-carrier-added (n.c.a.) [F-18]perchloryl fluoride ([F-18]FClO3) in superacidic media in the presence of KClO4 or anhydrous perchloric acid starting from [F-18]fluoride was demonstrated in this study. However. the radiochemical yields were low (1-6%) and poorly reproducible. Fluorosulphonic acid proved to be an essential intermediate as revealed by non-radioactive experiments. A key problem in the preparation of [F-18]FClO3 is the assumed kinetic inhibition due to the unfavourable stoichiometric ratio of the ClO4 moiety to [F-18]HSO3F. (C) 2007 Elsevier Ltd. All rights reserved.