Production Of ¹¹ C‐Labeled Amides Via “In‐Loop” ¹¹ C‐Carbonylation

The carbon-11 (¹¹C) labeling of benzamides holds great promise in the development of PET radiotracers given the prevalence of benzamides in bioactive molecules. This work establishes an improved automated route to carbon-11 labeled primary benzamides through carbonylative cross-coupling of aryl halides with carbon-11 carbon monoxide using electrophilic aroyl dimethylaminopyridinium salts as an intermediate. The methodology uses GE TRACERLab FX automated radiochemistry synthesis modules and allows for the synthesis of a variety of benzamide containing compounds, including known PET imaging agent [¹¹C]LY2795050, a KOR antagonist, in moderate to excellent radiochemical yields. This not only provides a practical means of synthesizing primary [¹¹C]benzamides, but it sets the stage for potential future applications in PET tracer synthesis. Overall, this development offers a versatile tool for generating ¹¹C-labeled compounds for PET imaging applications, thus opening new avenues in the field of molecular imaging and advancing our understanding of various biological processes.