Abstract: | The availability of no‐carrier‐added (n.c.a.) 1‐bromo‐4‐18F]fluorobenzene with high radiochemical yields is important for 18F‐arylation reactions using metallo‐organic 4‐18F]fluorophenyl compounds (e.g. of lithium or magnesium) or Pd‐catalyzed coupling. In this study, different methods for the preparation of 1‐bromo‐4‐18F]fluorobenzene by nucleophilic aromatic substitution reactions using n.c.a. 18F]fluoride were examined. Of six pathways compared, symmetrical bis‐(4‐bromphenyl)iodonium bromide proved most useful to achieve the title compound in a direct, one‐step nucleophilic substitution with a radiochemical yield (RCY) of 65% within 10 min. Copyright © 2004 John Wiley & Sons, Ltd. |