Synthesis and chemical reactivity of a 6-Me-3,2-hydroxypyridinone dithiazolide with primary amines: a route to new hexadentate chelators for hard metal(III) ions

A hydroxypyridinone building block, bifunctionalized with thiazoline, has been prepared from orthogonally protected 2-(3-(benzyloxy)-4-(ethoxycarbonyl)-6-methyl-2-oxopyridin-1(2H)-yl) acetic acid. The reactivity of the dithiazolide has been explored with two primary amines, leading to the synthesis and characterization of four new hexadentate ligands. Their complexes with selected hard trivalent ions pertinent to potential molecular imaging applications have been surveyed.