Synthesis of tritium-labeled PAM-43

The deuterium- and tritium-labeled PAM-43 was obtained in 23% yield and with a specific radioactivity of 132 Ci mmol–1. As determined by mass spectrometry, a PAM-43 molecule contained 80% of deuterium in 2,3-dihydrobenzofuran fragments, while the central fragment contained 20% of deuterium.