Protecting groups in the preparation of thiolate complexes of technetium

The nitrogen-sulfur ligand H 2 PIC(Acm) (N-(2-((2-(((acetylamino)methyl)thio)acetyl)amino)ethyl)-2-pyridinecarboxamide) reacted with (Bu 4 N) [TcOCl 4 ] in methanolic solution, yielding the neutral complex [TcO(PIC)] (oxo[N-(2-((2-mercaptoacetyl)amino)ethyl)-2-pyridinecarboxamido]technetium(V)) as a red crystalline solid. The thiol-protected derivatives H 2 PIC(Bzm) (Bzm=(benzoylamino)methyl) and H 2 PIC(Bzl) (Bzl=benzyl) similarly gave [TcO(PIC)] in near-quantitative yield. The X-ray structure of [TcO(PIC)] was determined