A simplified protocol for the automated production of 2‐[18F]fluoro‐3‐[2‐((S)‐3‐pyrrolinyl)methoxy]pyridine ([18F]nifene) on an IBA Synthera® module

• Published in: Journal of labelled compounds & radiopharmaceuticals 2024-01, Vol.67 (1), p.31-36
• Main Authors: Bhuiyan, Mohammed, Souris, Jeffrey, Kucharski, Anna, Freifelder, Richard, Mukherjee, Jogeshwar, Chen, Chin‐Tu
• Format: Article
• Language: English
• Subjects: [18F]nifene; Acetylcholine receptors (nicotinic); Cyclotrons; Decay; IBA Synthera; Microprocessors; Pyridines; Radiochemistry; Radiolabelling; radiosynthesis; Solvent extraction; Synthesis; Trifluoroacetic acid; α4β2 nicotinic acetylcholine receptor (nAChR) ligand
• ISSN: 0362-4803; 1099-1344
• DOI: 10.1002/jlcr.4071

The α4β2 nicotinic acetylcholine receptor (nAChR) ligand 2‐[18F]fluoro‐3‐[2‐((S)‐3‐pyrrolinyl)methoxy]pyridine ([18F]nifene) has been synthesized in 10% decay‐corrected radiochemical yield using the IBA Synthera® platform (IBA Cyclotron Solutions, Louvain‐la‐Neuve, Belgium) with an integrated fluidic processor (IFP). Boc‐nitronifene served as the precursor, and 20% trifluoroacetic acid (TFA) was used to deprotect the Boc‐group after radiolabeling. By omitting the solvent extraction step after radiolabeling, the process was simplified to a single step with no manual intervention. [18F]Nifene was obtained in decay‐corrected radiochemical yields of 10 ± 2% (n = 20) and radiochemical purity >99%. Typical specific radioactivities of 2700–4865 mCi/μmole (100–180 GBq/μmol) were measured at the end of synthesis; total synthesis times were about 1 h 40 min. The [18F]‐labeled α4β2 nicotinic acetylcholine receptor ligand [18F]nifene has been synthesized using an IBA Synthera® V2 module for use as a high‐affinity α4β2 receptor binding contrast agent for PET. This fully automated synthesis obviates all concerns of radiation exposure and readily enables the use of approximately 5.00 Ci starting activity to yield approximately 500 mCi in 10.0 mL, suitable for fractionation and injection. This simplified protocol can potentially be implemented in other automated synthesis modules.