Automated preparation of hypoxic cell marker [18F]FRP-170 by on-column hydrolysis

An automated synthesis for the preparation of the novel hypoxic cell marker, [18F]FRP-170 3, [18F]1-[2-fluoro-1-(hydroxymethyl)ethoxy]methyl-2- nitroimidazole, was developed using an on-column basic-hydrolysis step. The 18F-labeled protected intermediate 2 was retained on a Sep-Pak Plus C18 cartridge and, in the same cartridge at room temperature, hydrolyzed by NaOH for deacetylation to give [18F]FRP-170. The elution method from the cartridge was optimized for direct injection of the crude product into an HPLC column. Thus, [18F]FRP-170 was prepared in 20–30% decay-corrected radiochemical yield within 60 min.