Synthesis of 14 C- and 2 H-labelled CHF6001: A new potent PDE4 inhibitor.

An 8-step preparation of 14 C-labelled CHF6001, a potent phosphodiesterase 4 inhibitor in the treatment of respiratory diseases, is described. An overall yield of approximately 9% was obtained starting from copper[14 C]cyanide. The synthesis of a stable labelled version of CHF6001 is also reported using the commercially available trideuterated bromomethylcyclopropane as starting material.