THE LABELING OF A NOVEL TROPANE DERIVATIVE [C-11] NS-2214 (BMS-204756) - AN INHIBITOR OF THE DOPAMINE TRANSPORTER

The C-11-labelling of a novel tropane derivative thyl-8-azabicyclo[3.2 .1]octane-2-O-methyl-aldoxime (NS 2214 or BMS-204756), an inhibitor of the dopamine transporter (IC50 3 nM) is reported. nyl)-8-azabicyclo[3 .2.1]octane-2-O-methyl-aldoxime (NS 2262, either as the disulphate sal t with added base or as the free amine) was alkylated with [C-11]methy l iodide. The crude product was purified by HPLC using either a revers e phase or cyanopropyl stationary phase. Best results were obtained us ing the free amine as the labelling precursor and the cyanopropyl stat ionary phase for the HPLC purification. This resulted in the synthesis of radiochemically pure [C-11]NS 2214 with a decay corrected radioche mical yield of 24-30 %, specific activity > 50 GBq/mu mol (> 1.4 Ci/mu mol), and a total synthesis time of less than 30 min (counted from EO B).