Abstract
[11C]methyl iodide was originally produced by using LiAlH4 to reduce [11C]CO2 to [11C]methanol, followed by reaction with liquid hydriodic acid. However, it is difficult to obtain the desired high specific radioactivity of the end-product 11C-methylated tracer because the lithium reagent solution is so easily contaminated by atmospheric [12C]CO2. The introduction of high temperature gas-phase methodologies greatly enhanced the specific activity of 11C-labeled PET tracers by eliminating the lithium reagent entirely. Details for three commercially available gas-phase synthesis modules are provided and discussed with respect to ease-of-operation and preventative maintenance concerns. Lastly, C-11 target performance is discussed with respect to the in-target release of carrier [12C]carbon, the remaining obstacle to ultra-high specific activity for 11C-labeled PET tracers.
Keywords: Automation, Gas-phase production, Methyl iodide, Methyl triflate, Specific activity.
Call for Papers in Thematic Issues
Catalytic C-H bond activation as a tool for functionalization of heterocycles
The major topic is the functionalization of heterocycles through catalyzed C-H bond activation. The strategies based on C-H activation not only provide straightforward formation of C-C or C-X bonds but, more importantly, allow for the avoidance of pre-functionalization of one or two of the cross-coupling partners. The beneficial impact of ...read more
Related Books
Advances in Organic Synthesis
The Synthetic Methods, Structures, and Properties of the Ca-C σ Bond Organocalcium Containing Compounds
Advances in Organic Synthesis
Chemistry of Bipyrazoles: Synthesis and Applications
Advances in Organic Synthesis
Advanced Nanocatalysis for Organic Synthesis and Electroanalysis
Advances in Organic Synthesis
Advances in Organic Synthesis
12