Synthesis of N ‐(3‐[ 18 F]Fluoropropyl)‐2 β ‐carbomethoxy‐3 β ‐(4‐iodophenyl)nortropane ([ 18 F]FP‐ β ‐CIT)

N ‐(3‐[ 18 F]fluoropropyl)‐2 β ‐carbomethoxy‐3 β ‐(4‐iodophenyl)nortropane ([ 18 F]FP‐ β ‐CIT) was synthesized in a two‐step reaction sequence. In the first reaction, 1‐bromo‐3‐(nitrobenzene‐4‐sulfonyloxy)‐propane was fluorinated with no‐carrier‐added fluorine‐18. The resulting product, 1‐bromo‐3‐[ 18 F]‐fluoropropane, was distilled into a cooled reaction vessel containing 2 β ‐carbomethoxy‐3 β ‐(4‐iodophenyl)‐nortropane, diisopropylethylamine and potassium iodide. After 30 min, the reaction mixture was subjected to a preparative HPLC purification. The product, [ 18 F]FP‐ β ‐CIT, was isolated from the HPLC eluent with solid‐phase extraction and formulated to yield an isotonic, pyrogen‐free and sterile solution of [ 18 F]FP‐ β ‐CIT. The overall decay‐corrected radiochemical yield was 25 ± 5%. Radiochemical purity was > 98% and the specific activity was 94 ± 50 GBq/µmol at the end of synthesis. Copyright © 2006 John Wiley & Sons, Ltd.