Formation of the TcN 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 N3– 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.