One-Step Synthesis of <i>N</i>-Succinimidyl-4-[¹⁸F]Fluorobenzoate ([¹⁸F]SFB)

Abstract

Herein, we present a one-step labeling procedure of N-succinimidyl-4-[18F]-fluorobenzoate ([18F]SFB) starting from spirocyclic iodonium ylide precursors. Precursor syntheses succeeded via a simple one-pot, two-step synthesis sequence, in yields of approximately 25%. Subsequent 18F-nucleophilic aromatic labeling was performed, and radiochemical incorporations (RCCs) from 5−35% were observed. Purification could be carried out using HPLC and subsequent solid phase extraction. Radiochemical purity (RCP) of >95% was determined. The total synthesis time, including purification and formulation, was no longer than 60 min. In comparison to the established 3-step synthesis route of [18F]SFB, this one-step approach avoids formation of volatile radioactive side-products and simplifies automatization.

Keywords

• <i>N</i>-succinimidyl-4-[¹⁸F]fluorobenzoate
• [¹⁸F]SFB
• iodonium ylides
• fluorine-18
• PET