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Radiosyntheses and reactivities of novel [ 18 F]2‐fluoroethyl arylsulfonates
Author(s) -
Musachio John L.,
Shah Jay,
Pike Victor W.
Publication year - 2005
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.991
Subject(s) - chemistry , acetonitrile , aniline , radioligand , reactivity (psychology) , aryl , medicinal chemistry , alcohol , pyridine , nuclear chemistry , high performance liquid chromatography , organic chemistry , alkyl , receptor , medicine , biochemistry , alternative medicine , pathology
[ 18 F]2‐Fluoroethyl tosylate ([ 18 F]FEOX, X=Ts) is widely used for labeling radiotracers for positron emission tomography (PET). Little work has been reported on syntheses of other [ 18 F]2‐fluoroethyl arylsulfonates ([ 18 F]FEOX) that bear a less electron‐rich aryl group, even though these might offer enhanced reactivities. Thus, a series of novel [ 18 F]FEOX (X=benzenesulfonyl, brosyl, nosyl, 3,4‐dibromobenzenesulfonyl) were synthesized and reactivities compared to [ 18 F]FEOTs. Precursors for radiolabeling ( bis ‐ethylene glycol arylsulfonates) and reference FEOX were synthesized (alcohol+arylsulfonyl chloride+KOSiMe 3 in THF). Regardless of substitution pattern, [ 18 F]FEOX (110°C, 5 min, acetonitrile) were obtained in similar decay‐corrected isolated radiochemical yields (RCY; 47–53%). All [ 18 F]FEOX gave excellent RCYs (64–87%) of the dopamine uptake radioligand, [ 18 F]FECNT (130°C, 10 min, acetonitrile). The 3,4‐dibromobenzensulfonate gave the highest RCY of [ 18 F]FECNT (87%) and this HPLC‐purified labeling agent was used directly for efficient [ 18 F]FECNT production. When the secondary aniline of an amyloid probe (HM‐IMPY) or p ‐nitrophenol was reacted with [ 18 F]FEOX, RCYs were appreciably higher for brosylate and nosylate than for tosylate, while 3,4‐dibromobenzenesulfonate again gave the highest RCY. Owing to the high reactivity of the new [ 18 F]FEOX and their ease of syntheses via stable precursors, such agents (particularly 3,4‐dibromobenzenesulfonate) should be considered as alternatives to [ 18 F]FEOTs. Copyright © 2005 John Wiley & Sons, Ltd.