Several amide derivatives of phenylalanin and prolin were prepared as spacer/ligand compounds by reaction of unprotected or monoprotected aliphatic and aromatic diamines and monoamines with the succinimido esters of the corresponding N-protected amino acids. The formation of diacylated aliphatic diamines was fast under normal conditions. In the case of aromatic diamines the presence of a base is necessary. For the preparation of monoacylated diamines best results were obtained with monoprotected diamines. The acylated diamines were purified by column chromatography or by extraction.