Improved synthesis of pure [18F]fluoro-compounds for PET studies from bromo-compounds.
For preparing [18F]labeled compounds free from bromo-compounds for PET (positron emission tomography) studies, we propose the following two processes in which no separation is needed between the fluoro-compound and bromo-compound : (1). the bromo-compound is first converted into O-tosylate, which is then [18F]fluorinated; and (2). after [18F]fluorination of the bromo-compound, its excess is converted into an easily separable compound, e.g., phthalimide-compound. Direct tosylation with silver tosylate was effected in 65-85% yield for most commercial bromo-compounds, and with potassium phthalimide, the bromo-compounds in cold run were converted easily into phthalimide-compounds in 84-90% yield.
Takahashi
Toshihiro
T
Radioisotope Center, Niigata University, Asahimachi-dori 1-757, Niigata 951-8510, Japan. takatosi@med.niigata-u.ac.jp
Mizuno
Takashi
T
Ido
Tatsuo
T
Iwata
Ren
R
Watanabe
Ken-ichi
K
D002625:Chemistry, Organic / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000737:chemistry; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000302:isolation & purification; D007553:Isotope Labeling / Q000379:methods; D010797:Phthalimides / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000302:isolation & purification; D014055:Tomography, Emission-Computed / Q000379:methods; D014105:Tosyl Compounds / Q000737:chemistry
D005227:Fatty Acids; D005462:Fluorine Radioisotopes; D006842:Hydrocarbons, Brominated; D006845:Hydrocarbons, Fluorinated; D010797:Phthalimides; D019275:Radiopharmaceuticals; D014105:Tosyl Compounds; C037431:phthalimide; C003614:4-toluenesulfonyl fluoride