FAST CHEMISTRY IN MICROWAVE FIELDS - NUCLEOPHILIC F-18 RADIOFLUORINATIONS OF AROMATIC-MOLECULES

Nucleophilic aromatic radiofluorinations with [F-18]fluoride in a micr owave field were investigated in activated, partially deactivated and deactivated aromatic compounds. A coaxial resonance microwave cavity w as used to produce a well-defined electromagnetic field in the samples . The leaving group on the aromatic rings as well as the ortho, meta a nd para orientation of electron-withdrawing and electron-donating subs tituents were varied. Yields comparable to or better than those report ed for thermal treatments were obtained in very short reaction times ( less-than-or-equal-to 0.5 min, i.e. 1/20th-1/40th the thermal times) w ith very low microwave intensity and followed the trend of reactivity expected from the substrates activation for nucleophilic substitution.