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Updated: Jul 18, 2025

Enhancing Efficiency and Radiolabeling Yields of Carbon-11 Radioligands for Clinical Research Using the Loop Method
Published on: December 20, 2024
Automated production of 11C-labeled carboxylic acids and esters via "in-loop" 11C-carbonylation using GE FX synthesis
Tanpreet Kaur1, Jay S Wright1, Bradford D Henderson1
1Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
Abstract:
An in-loop 11C-carbonylation process for the radiosynthesis of 11C-carboxylic acids and esters from halide precursors has been developed. The reaction proceeds at room temperature under mild conditions and enables 11C-carbonylation of both electron deficient and electron rich (hetero)aromatic halides to provide 11C-carboxylic acids and esters in good to excellent radiochemical yields, high radiochemical purity, and excellent molar activity. The process has been fully automated using commercial radiochemistry synthesis modules, and application to clinical production is demonstrated via validated cGMP radiosyntheses of [11C]bexarotene and [11C]acetoacetic acid.
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