SYNTHESIS OF RACEMIC [ALPHA-C-11]AMPHETAMINE AND [ALPHA-C-11]PHENETHYLAMINE FROM [C-11] NITROALKANES

The synthesis of racemic [alpha-C-11]amphetamine and [alpha-C-11]phenethylamine from on-line produced [C-11]nitroethane and [C-11]nitromethane, respectively, is described. The condensations of no-carrier-added [C-11]nitroalkanes with benzaldehyde to form [beta-C-11]beta-nitrostyrenes were investigated under basic and acidic conditions. The [beta-C-11]beta-nitrostyrenes were reduced with lithium aluminium hydride to produce the corresponding saturated amines. Purification was performed with semi-preparative reversed-phase HPLC using a Suplex pKb-100 column. The total radiochemical yields were 7-20% (from EOB and decay-corrected) and 24-35% (based on [C-11]nitroalkanes and decay corrected) with a total synthesis time of 40-55 min. The specific radioactivity of [alpha-C-11]amphetamine and [alpha-C-11]phenethylamine at EOS was 200-1000 Ci/mmol (7.4-37 GBq/mumol) with a radiochemical purity >99%.