Direct Incorporation of [11C]CO2 into Asymmetric [11C]Carbonates

A novel carbon-11 radiolabelling methodology for the synthesis of the dialkylcarbonate functional group has been developed. The method uses cyclotron-produced short-lived [11C]CO2 (half-life 20.4 min) directly from the cyclotron target in a one-pot synthesis. Alcohol in the presence of base trapped [11C]CO2 efficiently forming an [11C]alkylcarbonate intermediate that subsequently reacted with an alkylchloride producing the di-substituted [11C]carbonate (34% radiochemical yield, determined by radio-HPLC) in 5 minutes from the end of [11C]CO2 cyclotron delivery.

Ion beam induced 18F-radiofluorination: straightforward synthesis of gaseous radiotracers for the assessment of regional lung ventilation using positron emission tomography

[18F]CF4 and [18F]SF6 are produced in a cyclotron target under proton irradiation. [18F]CF4 is suitable for assessing lung ventilation.

Filling and Recycling Apparatus of a Cyclotron Target with Enriched Krypton for Production of Radiopharmaceuticals

An apparatus for multiple filling of a cyclotron target with enriched Kr gas is described. The system is based on recycling pressurized gas by cryogenic pumping between the target tube and storage containers. The design and construction makes use of previous experience in the construction and operation of two analogue apparatuses for Xe124 high pressure gas targets, but major modifications have been incorporated, evoked by the different physical properties of Kr, by the character of the nuclear reaction, and by the demand for automation from the side of the end user.