Bis(4-benzyloxyphenyl)iodonium salts as effective precursors for the no-carrier-added radiosynthesis of 4-[18F]fluorophenol

4-[18F]Fluorophenol is a very useful intermediate compound for building-up more complex molecules bearing a 4-[18F]fluorophenoxy moiety. Bis(4-benzyloxyphenyl)iodonium salts proved very effective as labeling precursors for the radiosynthesis of this compound in no-carrier-added form. Starting from the bromide salt and performing the radiofluorination by conventional heating, 4-[18F]fluorophenol was obtained in an overall RCY of 43±12% while a yield of 52±3% was achieved more reliably starting from the tosylate salt and employing microwave heating. Highlights: • Bis(4-benzyloxyphenyl)iodonium salts served as precursors for 4-[18F]-fluorophenol. • Labeling was performed employing conventional and microwave heating. • Deprotection of the benzyl group was carried out by catalytic hydrogenation