Fully automated one-pot synthesis of [18F]fluoromisonidazole

A 18F-labeled fluoromisonidazole (1H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole, [18F]FMISO) was prepared via a one-pot, two-step synthesis procedure using a modified commercial Tracerlab FXF-N synthesis module. Nucleophilic fluorination of the precursor molecule 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulphonylpropanediol using no-carrier-added [18F]fluoride, followed by hydrolysis of the protecting group with 1 mol/L HCl and purification with Sep-Paks instead of HPLC, gave [18F]FMISO. The overall radiochemical yield with no decay correction was greater than 40%, the whole synthesis time was less than 40 min and the radiochemical purity was greater than 95%. The new automated synthesis procedure can be applied to the fully automated synthesis of [18F]FMISO using a commercial FDG synthesis module.