A high-yield automated radiosynthesis of the alpha-7 nicotinic receptor radioligand [¹⁸F]NS10743

[¹⁸F]NS10743, a promising and highly competitive α7 nAChR radioligand has been synthesised so far by microwave irradiation using a manual single-mode device followed by a palladium-catalyzed reduction of remaining nitro-precursor for HPLC separation purposes. For further preclinical and clinical use, regulated production of [¹⁸F]NS10743 by fully automated radiosynthesis is a crucial requirement. Therefore, we chose a commercial synthesis module and developed the automated radiosynthesis of [¹⁸F]NS10743. Besides evaluation of several radiosynthesis procedures, we performed an extensive HPLC study for quantitative separation of [¹⁸F]NS10743 from the corresponding nitro precursor. After implementation of the optimised procedure on a TRACERlabTM FX F-N synthesis module, [¹⁸F]NS10743 was obtained in high radiochemical purity (≥ 99%) with an overall radiochemical yield of 32.27% (n=3). The specific activities at the end of the synthesis were 571±17 GBq/µmol (n=3).