The reductive condensation of ammonium acetate with three molecules of N-Boc-O-benzyl-L-serinal (I) in the presence of sodium triacetoxyborohydride produced the tertiary amine (II). Subsequent removal of the Boc protecting groups of (II) by means of trifluoroacetic acid gave the tetra-amine (III). This was coupled with the (pyridylcarbonyl)thiazolidinethione (IV) to furnish the tris-pyridinecarboxamide (V). Cleavage of the benzyl ether groups of (V) was achieved by treatment of (V) with HBr in AcOH to yield (VI). This was finally complexed with Gd+3 ion to form the title gadolinium chelate.