Efficient Multigram Synthesis of the Bifunctional Chelating Agent (S)-1-p-Isothiocyanatobenzyl-diethylenetetraminepentaacetic Acid

We have developed and optimized the synthesis of the title compound, eliminating all HPLC purifications prior to the final product. The yield (and scale) of the synthesis was increased from 19% (200 mg) to 75% (26 g).