Automated radiosynthesis of the thiol-reactive labeling agent N-[6-(4-[¹⁸F]fluorobenzylidene)aminooxyhexyl]maleimide ([¹⁸F]FBAM)

The two-step radiosynthesis of N-[6-(4-[¹⁸F]fluorobenzylidene)aminooxyhexyl]maleimide ([¹⁸F]FBAM) was adapted to a remotely controlled synthesizer module. After optimization of reaction conditions as well as solid phase extraction based purification steps, the final [¹⁸F]FBAM was obtained in a decay-corrected radiochemical yield of 29±4% (related to [¹⁸F]fluoride, n=12) within a total synthesis time of 40min. The radiochemical purity of [¹⁸F]FBAM was in the range of 94-98%, the specific activity was determined with 13.4-17.2 GBq/µmol.