Solid-supported cyanoborohydride cartridges for automation of reductive amination radiochemistry

Abstract

A solid-supported cyanoborohydride cartridge was designed to facilitate the automated production of positron emission tomography (PET) radiotracers synthesised via reductive amination chemistry. Two compounds, N-(4-fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)ethan-1-amine ([¹⁸F]2) and 1,3,4,6-tetra-O-acetyl-2-(4-fluorobenzylamine)-2-deoxy-β-D-glucopyranose ([¹⁸F]4) were radiosynthesised efficiently using a GE FASTlab™ platform, obtained in >98% RCP in a total synthesis time of 75 min (from the start of synthesis) with RCY (non-decay corrected) of 7.5 ± 2.5% and 6.0 ± 1.1%, respectively. The cartridge method provides a convenient alternative to conventional powdered reducing agents typically used in reductive amination radiochemistry.