Preparation of N,N-Bis[2-[N',N'-Bis[(Tert-Butoxycarbonyl)Methyl]-Amino]Ethyl-L-Aspartic Acid: An Intermediate in the Synthesis of MRI Contrast Agents

Abstract

Abstract A preparation of DTPA carboxylic acid 1, a suitable intermediate in the synthesis of MRI contrast agents 2, is described starting from α-tert-butyl-β-benzyl-L-aspartate hydrochloride. In addition, an alternative procedure for the synthesis of bromide 3b is presented.