An Efficient Synthesis of Some 6-Substituted 4,8-Diaza-3,3,9,9-tetramethylundeca-2,10-dione Dioximes (Propylene Amine Oximes, PnAOs): Ligands for 99mTc Complexes Used in Structure Distribution Relationship (SDR) Studies

Article abstract of DOI:10.1016/S0040-4020(01)85336-9

Technetium complexes of the ligand PnAO <4,8-diaza-3,3,9,9-tetramethylundeca-2,10-dione dioximes (3)> are of interest as commercial radiopharmaceuticals.In general, PnAOs are synthesized by alkylation of a propylenediamine derivative with 3-chloro-3-methyl-2-nitrosobutane (2).This alkylation reaction proved to be low yielding.With modestly bulky substituents at the 2-position of 1,3-diaminopropane, little or none of the required PnAO was obtained.As a result, an alternative approach of the synthesis of PnAO was developed.This method involved the alkylation of the propylenediamine with 3-bromo-3-methylbutan-2-one (18) followed by oximation of the resulting diamine-diketone (19).By this method, PnAOs were prepared in good yield, even with bulky C-2 substituents.Fourteen PnAO derivatives were prepareed by this method.We also describe the syntheses of several new propylenediamine dervatives.