Automated radiosynthesis of [¹¹C]L-deprenyl-D₂ and [¹¹C]D-deprenyl using a commercial platform

Two ¹¹C-labelled PET tracers, (R)-N-[¹¹C]methyl-N-(3,3-dideuteropropargyl)-1-phenylpropan-2-amine ([¹¹C]L-deprenyl-D_2, [¹¹C]DED) and (S)-N-[¹¹C]methyl-N-propargyl-1-phenylpropan-2-amine ([¹¹C]D-deprenyl, [¹¹C]DDE) were synthesised. One step N-alkylation with [¹¹C]MeI or [¹¹C]MeOTf was performed using the automated platform TRACERlab® FX-C Pro. The labelled products were obtained with (37±15)% (n=10) (end of synthesis, decay corrected from [¹¹C]MeI) radiochemical yields from [¹¹C]MeI after 38±3 min synthesis time. In all cases, radiochemical purity was over 99% when [¹¹C]MeOTf was used. This synthesis using a commercial platform makes these tracers more accessible for clinical research purposes. - Highlights: • Two ¹¹C PET tracers, [¹¹C]L-deprenyl-D₂ and [¹¹C]D-deprenyl, were synthesised. • Labelling conditions were tested: methylating agent, reaction temperature, solvent and base. • Radiotracers were synthesised in a commercial platform using [¹¹C]MeOTf. • A facile organic synthesis of [¹¹C]D-deprenyl precursor was developed.