Synthesis of hexadentate ligands via the in situ formation of 1-hydroxy benzotriazolyl active ester in the presence of 2-(1H-benzotriazol-1-yl)-1, 1, 3, 3-tetramethyluronium tetrafluoroborate, TBTU as a coupling agent is described. The pKa values and distribution coefficient values (1-octanol/water) of the ligands and the stability constants of their iron (III) complexes are reported.
![N-[2-[bis[2-[[2-(3-hydroxy-2-oxopyridin-1-yl)acetyl]amino]ethyl]amino]ethyl]-2-(3-hydroxy-2-oxopyridin-1-yl)acetamide Structure](https://image.chemsrc.com/caspic/465/99110-76-6.png)
