Fast Production of Highly Reactive No‐Carrier‐Added [¹⁸F]Fluoride for the Labeling of Radiopharmaceuticals

Abstract

Doing without water: The 18F labeling of radiopharmaceuticals requires nearly anhydrous solutions of [18F]fluoride. Aqueous K2CO3 is generally used to elute [18F]fluoride from an anion‐exchange resin. Replacing aqueous K2CO3 with strong organic bases, such as the phosphazene base P2Et (conjugate acid shown), enabled the recovery of highly reactive [18F]fluoride and avoided the azeotropic evaporation of water, which is very difficult on a microchip device.

Copper/TEMPO-Catalyzed Aerobic Alcohol Oxidation: Mechanistic Assessment of Different Catalyst Systems

“…The resulting Cu II species ( 6 ) lies off the catalytic cycle and must access the active Cu II –alkoxide intermediate via reaction with alcohol and the weak base, NMI. In the case of Cu II /DBU, the acid is DBUH+ OTf − , which is substantially less acidic ( p K a = 24 in MeCN 14 ). These considerations account for the data shown in Figure 6, which show that NMIH + strongly inhibits the reaction while DBUH + lacks this inhibitory effect.…”

Facile calculation of specific rate constants and activation energies of 18F-fluorination reaction using combined processes of coat-capture–elution and microfluidics

“…11 Recently, a method of using special base solutions in MeCN showed very efficient elution of the captured [ 18 F]fluoride from the resin and high radiolabeling yield, and thus is regarded as an important progress in 18 Flabeling. 12 Another important method was developed by Aerts et al, 13 which could be represented as a Coat-CaptureeElution (CCE) process (Fig. 1b).…”

Automated concentration of [18F]fluoride into microliter volumes

“…This method can be considered an alternative to other approaches that have previously been reported for reducing water and/or base content for macroscale reactions. For example, Lemaire et al (2010) demonstrated nearly quantitative elution of [ 18 F]fluoride from a conventional QMA cartridge with a solution containing organic base in MeCN with either a small amount of alcohol or water (0.2–2.5%). The eluate was directly used in fluorination reactions and resulted in high yields without the need for azeotropic drying.…”