The reaction of diethylenetriamine-pentaacetic acid (I) with acetic anhydride in hot pyridine gives the dianhydride (II), which is treated with 2-methoxyethylamine (III) in hot acetonitrile or isopropanol to yield the diamide ligand (IV). Finally, this compound is treated with Gd2O3 in hot water/isopropanol/acetonitrile or other mixed solvents to afford the target gadolinium complex.