Comparison of pathways to the versatile synthon of no-carrier-added 1-bromo-4-[18F]fluorobenzene

The availability of no-carrier-added (n.c.a.) 1-bromo-4-[F-18]fluorobenzene with high radiochemical yields is important for F-18-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-[F-18]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 (C) 2004 John Wiley Sons, Ltd.