Radiosynthesis and reactivity of N-[11C]methyl carbamoylimidazole

N-Methyl carbamoylimidazole is a safe and practical alternative to methyl isocyanate for carbamoylation reactions. We have developed a new chemical route for its synthesis from methyl iodide and applied this to the synthesis of N-[C-11]methyl carbamoylimidazole as a new [C-11]synthon to radiolabel biomolecules for PET imaging research. N-[C-11]methyl carbamoylimidazole was prepared from [C-11]methyl iodide in 70-74% radiochemical yield (decay corrected) and can be used in situ for further reaction without purification. The reactivity of N-[C-11]methyl carbamoylimidazole was demonstrated in a series of [C-11]carbamoylation reactions.