Palladium-Mediated¹¹C-Carbonylations Using Aryl Halides and Cyanamide

A robust and high-yielding radiochemical synthesis of ¹¹C-N-cyanobenzamides using a palladium-mediated aminocarbonylation with ¹¹C-CO, aryl halides and cyanamide is described. The bidentate ligand 1,1′-bis(diphenylphosphino)ferrocene provided ¹¹C-N-cyanobenzamides from aryl-iodides, bromides, triflates and even chlorides in 28–79% radiochemical yield after semi-preparative HPLC. To further highlight the utility of this method, novel ¹¹C-N-cyanobenzamide analogs of flufenamic acid, meflanamic acid, dazoxiben and tamibarotene were synthesized in 34–71% radiochemical yields.