Synthesis ofmeta-iodobenzyl [11C]guanidine

An efficient and fully automated one-pot method for the synthesis of 3-iodobenzyl [C-11]guanidine (C-11]MIBG) was developed. Starting from [C-11]cyanogen bromide, [C-11]MIBG was obtained in 62 % radiochemical yield and a radiochemical purity higher than 98 % via the intermediate 3-iodobenzyl [C-11]cyanamide. The synthesis time was 40 min counted from the end of bombardment and the product was obtained with a specific radioactivity of 3.5 Ci/mu mol (130 GBq/mu mol) at the end of synthesis.