A cryotrap as flow reactor for synthesis of 211At labelled compounds

A new simplified approach for the preparation of 211At-labelled compounds is presented. The labelling procedure is carried out entirely in a Teflon capillary which also serves as a cryotrap. Two organic astatine compounds were synthesized by this method: 5-[211At]astato-2′-deoxyuridine (AUdR) and N-succinimidyl-4-[211At]astatobenzoate (SAB), starting from their respective stannylated precursors. The first reaction was performed in aqueous solution and the latter in an organic solvent using Iodogen as the oxidant in both cases. Overall radiochemical yields were approximately 75% for AUdR and approximately 70% for SAB.