Synthesis of a phenolic precursor and its efficient O ‐[ 18 F]fluoroethylation with purified no‐carrier‐added [ 18 F]2‐fluoroethyl brosylate as the labeling agent

[ 18 F]2‐Fluoroethyl‐ p ‐toluenesulfonate also called [ 18 F]2‐fluoroethyl tosylate has been widely used for labeling radioligands for positron emission tomography (PET). [ 18 F]2‐Fluoroethyl‐4‐bromobenzenesulfonate, also called [ 18 F]2‐fluoroethyl brosylate ([ 18 F]F(CH 2 ) 2 OBs), was used as an alternative radiolabeling agent to prepare [ 18 F]FEOHOMADAM, a fluoroethoxy derivative of HOMADAM, by O ‐fluoroethylating the phenolic precursor. Purified by reverse‐phase HPLC, the no‐carrier‐added [ 18 F]F(CH 2 ) 2 OBs was obtained in an average radiochemical yield (RCY) of 35%. The reaction of the purified and dried [ 18 F]F(CH 2 ) 2 OBs with the phenolic precursor was performed by heating in DMF and successfully produced [ 18 F]FEOHOMADAM, after HPLC purification, in RCY of 21%. Copyright © 2013 John Wiley & Sons, Ltd.