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How to increase the reactivity of [ 18 F]fluoroethyl bromide: [ 18 F]fluoroethylation of amine, phenol and amide functional groups with [ 18 F]FEtBr, [ 18 F]FEtBr/NaI and [ 18 F]FEtOTf
Author(s) -
Zhang MingRong,
Furutsuka Kenji,
Yoshida Yuichiro,
Suzuki Kazutoshi
Publication year - 2003
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.703
Subject(s) - chemistry , amide , amine gas treating , reactivity (psychology) , bromide , phenol , medicinal chemistry , nucleophile , substrate (aquarium) , organic chemistry , catalysis , medicine , oceanography , alternative medicine , pathology , geology
[ 18 F]Fluoroethyl bromide ([ 18 F]FEtBr) is a useful synthetic precursor to synthesize 18 F‐labeled compounds. However, the lower reactivity of [ 18 F]FEtBr with amine, phenol and amide functional groups than that of [ 11 C]CH 3 I partly limits its wide application in the synthesis of [ 18 F]fluoroethylated compounds. The aim of this study was to increase the reactivity of [ 18 F]FEtBr with various nucleophilic substrates for PET tracers containing amine, phenol and amide moieties. The present strategies included (1) adding NaI into the reaction mixture of [ 18 F]FEtBr and substrate, where [ 18 F]FEtI is reversibly formed and becomes more reactive; (2) converting [ 18 F]FEtBr into much more reactive [ 18 F]FEtOTf, similar to conversion of [ 11 C]CH 3 I into [ 11 C]CH 3 OTf. By these efforts, the [ 18 F]fluoroethylation efficiency of various substrates containing amine, phenol and amide groups with [ 18 F]FEtBr/NaI and [ 18 F]FEtOTf was significantly improved, compared with the corresponding reaction efficiency with [ 18 F]FEtBr. Copyright © 2003 John Wiley & Sons, Ltd.