The nucleophilic substitution reaction for [18F]fluoride-ion on the series of N6-benzoyl-2′,3′-isopropylideneadenosine-5′-sulfonates

The reaction of the nca [F-18]fluoride ion was investigated toward a series of NI-benzoyl 2,3'-isopropylidene-adenosine-5-sulfonates including the methane-(mesylate),p-toluene-(tosylate),p-nitro-benzene-(nosylate)- and 2,2,2-trifluoro-ethane-sulfonate (tresylate) derivatives under usual nucleophilic substitution conditions. In these reactions cyclisation of the title compounds was observed whilst the radiofluorination took place only with low yield. The fluorine-18 uptake was found to be 1.17% for mesylate, 1.46% for tosylate, 0.99% for nosylate and 0.40% for tresylate under the conditions applied.