Synthesis and [C-11]-radiolabelling of dechloro-epibatidine and 2PABH, twopotential radioligands for studying the central nAChRs in vivo.

The two epibatidine (EPB) analogues dechloro-epibatidine (DC1-EPB) and 2PAB H were synthesised via a two step reaction starting from N-methoxycarbonyl- 7-azabicyclo[2.2.1]heptene. The radiochemical syntheses of [C-11]N-methylat ed derivatives was performed using the classical methylating agent [C-11]CH 3I in acetonitrile. The radiochemical yield ranged from 5 to 10 % (decay co rrected from [C-11]CH3I) and was fully sufficient for small animal experime nts. High specific activities in the range of 140 to 360 GBq/mu mol at EOS tend of synthesis) were obtained. The radiosynthesis, semipreparative HPLC, formulation and quality control were completed in an average time of 35 mi n.