Diethylenetriaminepentaacetic acid → HCID 88176279, compound

Participants

Reaction Steps

O-(4-Hydroxyphenyl)-3,5-diiodo-L-tyrosine methyl ester, prepared according to Example 4 Step A, was reacted with N,N-bis[2-[bis[2-(1,1-dimethylethoxy)-2-oxoethyl]amino]ethyl]-L-glutamic acid 1-(1,1-dimethyl-ethyl) ester (prepared according to: Anelli P. L., Fedeli F., Gazzotti O., Lattuada L., Lux G. and Rebasti F., “L-Glutamic Acid and L-Lysine as Useful Building Blocks for the Preparation of Bifuctional DTPA-like Ligand”, Bioconjugate Chem. (1999), 10, 137-140), diethylphosphoryl cyanide (DEPC) and ethyldiisopropylamine (DIEA), in DMF, under nitrogen atmosphere at 0° C. After purification by flash chromatography, the pentaester was deprotected at first with TFA in CH2Cl2 at room temperature for 47 h, then with 2 M LiOH for 21 h. The solution was acidified to pH 3.3 with aq. HCl and loaded onto an Amberlite® XAD 1600 resin column. Eluting with a H2O/CH3CN gradient afforded the ligand.

Provenance & Evidence