Aryltrimethylammonium trifluoromethanesulfonates as precursors to aryl [¹⁸F]fluorides: Improved synthesis of [¹⁸F]GBR‐13119

Aromatic nucleophilic substitution of various trimethylammonium trifluoromethanesulfonates with [ 18 F]fluoride has been evaluated. Fluorinations were studied over a temperature range of 45–165°C, with decay corrected yields ranging from 20–80%. [ 18 F]GBR 13119, 1‐[2‐{(4‐[ 18 F]fluorophenyl)(phenyl)methoxy}ethyl]‐4‐(3‐phenylpropyl)piperazine, a potential radio‐tracer for the dopamine uptake system, has been prepared in no‐carrier‐added form from 4‐N,N,N,‐trimethylaniliniumphenylmethanone trifluoromethanesulfonate. Purification by solid‐phase techniques yielded the product in 20% decay corrected radiochemical yield and >98% radiochemical and chemical purity without HPLC.