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Updated: May 5, 2026

Enhancing Efficiency and Radiolabeling Yields of Carbon-11 Radioligands for Clinical Research Using the Loop Method
Published on: December 20, 2024
An improved synthesis of [11C]MENET via Suzuki coupling with [11C]methyl iodide
Fanxing Zeng1, Ronald J Voll, Ronald J Crowe
1Department of Radiology and Imaging Sciences, Emory University, 1841 Clifton Road NE, Atlanta, GA, 30329, USA.
Abstract:
[(11) C]MENET, a promising norepinephrine transporter imaging agent, was prepared by Suzuki cross coupling of 1 mg N-t-Boc pinacolborate precursor with [(11) C]CH3 I in DMF using palladium complex generated in situ from Pd2 (dba)3 and (o-CH3 C6 H4 )3 P together with K2 CO3 as the co-catalyst, followed by deprotection with trifluoroacetic acid. This improved radiolabeling method provided [(11) C]MENET in high radiochemical yield at end of synthesis (EOS, 51 ± 3%, decay-corrected from end of (11) CH3 I synthesis, n = 6), moderate specific activity (1.5-1.9 Ci/µmol at EOS), and high radiochemical (>98%) and chemical purity (>98%) in a synthesis time of 60 ± 5 min from the end of bombardment.
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