A bicyclic tetraazatriacetic chelating agent containing a thioalkyl pendant group was prepared. Four synthetic routes have been investigated via a Mitsunobu reaction from 2, 4- [bishydroxymethyl]-3-hydroxy-pyridine 1. Deprotection of trityl thioether compound 5c led to ligand 6c in 22% overall yield from the starting 3-hydroxypyridine.