“…Molecules labeled with tritium (T, 3 H, half-life:1 2.3 years) [1] are in perpetually high demand for the study of protein receptor-ligand interactions, [2,3] autoradiographic imaging of molecular interactions in biological tissue, [3,4] and the investigation of molecular absorption, distribution, metabolism and excretion (ADME). [5][6][7] To enable such applications quickly and with low cost, particularly in academic and industrial settings with rapid turnover cycles for evaluation of candidate pharmaceuticals and imaging tracers,direct C À Htritiation on the final molecule of interest is ad esired synthetic approach. [7][8][9][10][11] Thep referred source of tritium is tritium gas (T 2 ), because T 2 is the low cost synthetic precursor of other tritium building blocks,and is practical to handle on micromole scale with commercially available manifolds.F urthermore,T 2 is available in > 99 %i sotopic purity,w hich facilitates the synthesis of high specific activity compounds used in binding and autoradiography studies (> 15 Ci mmol À1 ,a pprox.…”