Expedient synthesis of [¹⁸F]-labeled α-trifluoromethyl ketones

Several [¹⁸F]-labeled α-trifluoromethyl ketones have been synthesized. Reactions of 2,2-difluoro-1-aryl-1-trimethylsiloxyethenes (1a-d) with [¹⁸F]-F₂ at low temperature produced [ ¹⁸F]-labeled α-trifluoromethyl ketones (2a-d). Radio-labeled products were isolated by purification with column chromatography in 22-28% yields, decay corrected (d.c.) in three runs per compound. Radio-chemical purity was > 99% with specific activities 15-20 GBq/mmol at the end of synthesis (EOS). The synthesis time was 35-40 min from the end of bombardment (EOB). This one-step simple method is highly useful for the radiochemical synthesis of potential biologically active [¹⁸F]-labeled α-trifluoromethyl ketones for PET imaging.