Microfluidic reactions using [11C]carbon monoxide solutions for the synthesis of a positron emission tomography radiotracer

Microfluidic technology has been used to perform [C-11]carbonylation reactions using solutions containing [C-11]CO in the form of the complex, copper(I)tris(3,5-dimethylpyrazolyl)borate[C-11]carbonyl (Cu(Tp*)[C-11]CO). The synthesis of the model compound [C-11]N-benzylbenzamide and the known tracer molecule [C-11]trans-N-[5-(2-flurophenyl)-2-pyrimidinyl]-3-oxospiro[5-azaisobenzofurane-1(3H),1'-cyclohexane]-4'-carboxamide ([C-11]MK-0233), a ligand for the neuropeptide Y Y5 receptor, have been performed using this technique. Following semi-preparative HPLC purification and reformulation, 1262 +/- 113 MBq of [C-11]MK-0233 was produced at the end of the synthesis with a specific activity of 100 +/- 30 GBq mu mol(-1) and a >99% radiochemical purity. This corresponds to a decay corrected radiochemical yield of 7.2 +/- 0.7%. Using a 3 mL vial as the reaction vessel, and following semi-preparative HPLC purification and reformulation, 1255 +/- 392 MBq of [C-11]MK-0233 was produced at the end of the synthesis with a specific activity of 100 +/- 15 GBq mu mol(-1) and a >99% radiochemical purity. This corresponds to a decay corrected radiochemical yield of 7.1 +/- 2.2%.