Improved Synthesis Of [F-18]Flett Via A Fully Automated Vacuum Distillation Method For [F-18]2-Fluoroethyl Azide Purification

The synthesis of [F-18]2-fluoroethyl azide and its subsequent click reaction with 5-ethyny1-2'-deoxyuridine (EDU) to form [F-18]FLETT was performed using an iPhase FlexLab module. The implementation of a vacuum distillation method afforded [F-18]2-fluoroethyl azide in 87 +/- 53% radiochemical yield. The use of Cu(CH3CN)(4)PF6 and TBTA as catalyst enabled us to fully automate the [F-18]FLETT synthesis without the need for the operator to enter the radiation field. [F-18]FLETT was produced in higher overall yield (413 +/- 6.5%) and shorter synthesis time (67 min) than with our previously reported manual method (32.5 +/- 2.5% in 130 min). (C) 2014 Elsevier Ltd. All rights reserved.