Synthesis of No-Carrier-Added 4-[18F]Fluorophenol from 4-Benzyloxyphenyl-(2-thienyl)iodonium Bromide

Abstract

4-[18F]Fluorophenol is a versatile synthon for the synthesis of more complex radiopharmaceuticals bearing a 4-[18F]fluorophenoxy moiety. In order to prepare 4-[18F]fluorophenol in no-carrier-added (n.c.a.) form only a nucleophilic labelling method starting from [18F]fluoride is suitable. In this paper a new, two step radiosynthesis starting from 4-benzyloxyphenyl-(2-thienyl)iodonium bromide and [18F]fluoride with subsequent deprotection is described, yielding n.c.a. [18F]fluorophenol in 34 to 36% radiochemical yield.

Keywords

• fluorine-18
• 4-[18F]fluorophenol
• diaryl iodonium salts
• radiosynthesis
• positron emission tomography