Tos-Nos-Mos: Synthesis of different aryl sulfonate precursors for the radiosynthesis of the alpha7 nicotinic acetylcholine receptor radioligand [18F]NS14490

Insights into Elution of Anion Exchange Cartridges: Opening the Path toward Aliphatic 18F-Radiolabeling of Base-Sensitive Tracers

“…As mentioned previously, different leaving groups can influence the labeling yield substantially, but no trend with respect to increased RCY has been observed. The yields varied on a case-by-case basis depending on the individual molecular structure of the precursor . To facilitate the reaction, the solvent was further changed to t -BuOH mixed with DMSO which decreased the evaporation of solvent during automated synthesis while maintaining the RCC (Table S20).…”

“…The yields varied on a case-by-case basis depending on the individual molecular structure of the precursor. 58 To facilitate the reaction, the solvent was further changed to t -BuOH mixed with DMSO which decreased the evaporation of solvent during automated synthesis while maintaining the RCC ( Table S20 ). The nosylate precursor with t -BuOH/DMSO and the low basic elution condition ( 4A ) resulted in a RCY of approximately 22% ( Figure 4 ) .…”

Imaging Cholinergic Receptors in the Brain by Positron Emission Tomography

“…Recently, [ 18 F]NS14490 ( 58 ) was developed as a 18 F-labeled α7 nAChR PET ligand with high binding affinity and selectivity ( K i = 2.5 nM for α7 nAChRs; K i > 1 μM for α4β2 nAChRs). 151 However, subsequent in vivo evaluation revealed limited brain uptake of the radioligand. Ex vivo biodistribution studies in mice demonstrated a low brain uptake level of only 0.16%ID/g at 5 min p.i.…”