Phenyliodonium ylide derivatives substituted with electron donating as well as electron withdrawing groups on the aromatic ring are shown for use as precursors in aromatic nucleophilic substitution reactions. The iodonium ylide group is substituted by nucleophiles such as halide ions to provide the corresponding haloaryl derivatives. No-carrier-added [F-18]fluoride ion exclusively substitutes the iodonium ylide moiety in these derivatives and provides high specific activity F-18 labeled fluoro derivatives. Protected L-dopa-6-iodonium ylide derivative have been synthesized as a precursors for the preparation of no-carrier-added 6-[F-18]fluoro-L-dopa. The iodonium ylide group in this L-dopa.derivative is nucleophilically substituted by no-carrier-added [F-18]fluoride ion to provide a [F-18]fluoro intermediates which upon acid hydrolysis yielded 6-[F-18]fluoro-L-dopa.
苯基
碘鎓
亚胺衍
生物在芳香环上取代电子供体和电子吸引基,可用作芳香族亲核取代反应的前体。
亚胺基团被卤离子等亲核试剂取代,以提供相应的卤代芳基衍
生物。在这些衍
生物中,无载体添加的[F-18]
氟离子仅取代
碘鎓
亚胺基团,并提供高比活度的F-18标记的
氟代衍
生物。保护的
L-多巴-6-
碘鎓
亚胺衍
生物已被合成为制备无载体添加的6-[F-18]
氟-
L-多巴的前体。在这个
L-多巴衍
生物中,
碘鎓
亚胺基团被无载体添加的[F-18]
氟离子亲核取代,以提供一个[F-18]
氟中间体,通过酸
水解产生6-[F-18]
氟-
L-多巴。