Efficient Reductive N- 11 C-Methylation Using Arylamines or Alkylamines and In Situ-Generated [ 11 C]Formaldehyde From [ 11 C]Methyl Iodide.

Autor: Kikuchi T; Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan., Okamura T; Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan., Zhang MR; Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan.
Jazyk: angličtina
Zdroj: Journal of labelled compounds & radiopharmaceuticals [J Labelled Comp Radiopharm] 2024 Jun 15; Vol. 67 (7), pp. 254-262. Date of Electronic Publication: 2024 May 04.
DOI: 10.1002/jlcr.4095
Abstrakt: Reductive N- 11 C-methylation using [ 11 C]formaldehyde and amines has been used to prepare N- 11 C-methylated compounds. However, the yields of the N- 11 C-methylated compounds are often insufficient. In this study, we developed an efficient method for base-free reductive N- 11 C-methylation that is applicable to a wide variety of substrates, including arylamines bearing electron-withdrawing and electron-donating substituents. A 2-picoline borane complex, which is a stable and mild reductant, was used. Dimethyl sulfoxide was used as the primary reaction solvent, and glacial acetic acid or aqueous acetic acid was used as a cosolvent. While reductive N- 11 C-methylation efficiently proceeded under anhydrous conditions in most cases, the addition of water to the reductive N- 11 C-methylation generally increased the yield of the N- 11 C-methylated compounds. Substrates with hydroxy, carboxyl, nitrile, nitro, ester, amide, and phenone moieties and amine salts were applicable to the reaction. This proposed method for reductive N- 11 C-methylation should be applicable to a wide variety of substrates, including thermo-labile and base-sensitive compounds because the reaction was performed under relatively mild conditions (70°C) without the need for a base.
(© 2024 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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