Formation of the TcN multiple bond from the reaction of ammonium pertechnetate with S-methyl dithiocarbazate and its application to the preparation of technetium-99m radiopharmaceuticals

Abstract

The reaction of pertechnetate with the S-methyl ester of dithiocarbazic acid, H₂N–NR–C(S)SCH₃(R = H or CH₃), in the presence of HCl and triphenylphosphine, affords the technetium(V) nitrido complex [TcNCl₂(PPh₃)₂] in high yield. Derivatives of S-methyl dithiocarbazate of the type R¹(R²)CN–NR³–C(S)SCH₃, where R¹=o-C₆H₄OH, C₆H₅, or CH₃, R²= H or CH₃, and R³= H or CH₃, behave as sources of N^3– groups, giving rise to a variety of technetium complexes containing the TcN multiple bond. These reactions apply equally well to the preparation of technetium-99m radiopharmaceuticals containing the TcN group, at the non-carrier-added level of nuclear medicine.