A new practical tritium labelling procedure using sodium borotritide and tetrakis(triphenylphosphine)palladium(0)

Abstract

Abstract A simple, mild and versatile new tritium ( 3 H) labelling method on a micro scale using sodium borotritide (NaB 3 H 4 ) and a transition–metal complex catalyst is described. 3 H‐labelled compounds were prepared effectively by 3 H hydrogenolysis of appendant functional groups in target compounds. The appendant functional group such as bromo, iodo or sulfonate in various target compounds can be replaced by tritium ( 3 H) in moderate yields. The new method was established by optimization of the reaction conditions and examination of its applicability using four types of model substrates in tracer runs. Then, various drug candidates and ligands for drug discovery were labelled with tritium on a micro scale. The specific radioactivity of the 3 H‐labelled compounds used for the studies on receptor binding ranged from 12 to 20 Ci/mmol. Copyright © 2001 John Wiley & Sons, Ltd.