[11C]copper(I) cyanide: a new radioactive precursor for 11C-cyanation and functionalization of haloarenes

Radiosynthesis of [cyano-11C]benzonitriles, [carboxyl-11C]benzoic acids, [carbonyl-11C]benzamides and [tetrazoyl-11C]5-biphenyl-1H-tetrazoles are described. [Cyano-11C]benzonitriles were prepared using the Rosenmund-von Braun reaction in one step from [11C]hydrogen cyanide via [11C]copper(I) cyanide in 2 min. [Carboxyl-11C]benzoic acids and [carbonyl-11C]benzamides were prepared from [cyano-11C]benzonitrile-complex using basic hydrogen peroxide for 3 min in N,N-dimethylformamide at 180 and 80°C, respectively. [Tetrazoyl-11C]5-biphenyl-1H-tetrazoles were obtained from [cyano-11C]benzonitrile-complexes in 7 min by cyclization with trimethyltin azide followed by acid hydrolysis at 180°C. These labelled compounds were obtained in a one-pot procedure with good average specific radioactivities [500 mCi/μmol (18.5 GBq/μmol) at the end of synthesis] and in satisfactory average radiochemical yields (24–69%) at 40 min from the end of radionuclide production. This new radioactive precursor. [11C]copper(I) cyanide, should give access to new 11C-labelled ligands for positron emission tomography.