Strategies for the Production of [11C]LY2795050 for Clinical Use

This report describes a comparison of four different routes for the clinical-scale radiosynthesis of the κ-opioid receptor antagonist [11C]­LY2795050. Palladium-mediated radiocyanation and radiocarbonylation of an aryl iodide precursor, as well as copper-mediated radiocyanation of an aryl iodide and an aryl boronate ester, have been investigated. Full automation of all four methods is reported, each of which provides [11C]­LY2795050 in sufficient radiochemical yield, molar activity, and radiochemical purity for clinical use. The advantages and disadvantages of each radiosynthesis method are compared and contrasted.