One-pot synthesis of 11C-labelled primary benzamides via intermediate [11C]aroyl dimethylaminopyridinium salts.

Electrophilic 11 C-labelled aroyl dimethylaminopyridinium salts, obtained by carbonylative cross coupling of aryl halides with [ 11 C]carbon monoxide, were prepared for the first time and shown to be valuable intermediates in the synthesis of primary [ 11 C]benzamides. The methodology furnished a set of benzamide model compounds, including the two poly (ADP-ribose) polymerase (PARP) inhibitors niraparib and veliparib, in moderate to excellent radiochemical yields. In addition to providing a convenient and practical route to primary [ 11 C]benzamides, the current methodology paves the way for future application of [ 11 C]aroyl dimethylaminopyridinium halide salts in PET tracer synthesis.