"synthetic routes with moderate to high yields have been developed to produce the reference standard 9 demethylated precursor 8 and target tracer [11C]9. The radiosynthesis employed [11C]CH3OTf for N-[11C]methylation at the piperazin position of the desmethyl precursor followed by product purification and isolation using a semi-preparative RP HPLC combined with SPE. [11C]9 was obtained in high radiochemical yield radioc"xsd:string