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

Microfluidic technology has been used to perform (11)C]carbonylation reactions using solutions containing (11)C]CO in the form of the complex, copper(i)tris(3,5-dimethylpyrazolyl)borate-(11)C]carbonyl (Cu(Tp*)(11)C]CO). The synthesis of the model compound (11)C]N-benzylbenzamide and the known tracer molecule (11)C]trans-N-5-(2-flurophenyl)-2-pyrimidinyl]-3-oxospiro5-azaisobenzofurane-1(3H),1'-cyclohexane]-4'-carboxamide ((11)C]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 (11)C]MK-0233 was produced at the end of the synthesis with a specific activity of 100 ± 30 GBq μmol(-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 (11)C]MK-0233 was produced at the end of the synthesis with a specific activity of 100 ± 15 GBq μmol(-1) and a >99% radiochemical purity. This corresponds to a decay corrected radiochemical yield of 7.1 ± 2.2%.