Preparation of tritium labelled benzamide dopamine‐D2 lignads at high specific activity

Abstract
A method for the preparation of tritium labelled potential neuroleptics of the benzamide class possessing highly potent dopamine‐ D2 binding properties, is described. The pyrrolidine moiety of the molecule is labelled with tritium by hydrogenation, to a specific activity of up to 58 Ci/mmol and subsequently reacted with an acid chloride. The specificity of the label is confirmed by 3H‐NMR.