For this research, a bromo-functionalized 18-membered macrocyclic ligand was synthesized and analyzed with upon a Ultra-High Performance Liquid Chromatography platform coupled with mass and fluorescence detectors. These reported tripyrinophane ligands are desired for their very stable lanthanide (III) complexes, such as europium and terbium, for their applications in aqueous solutions at a physiological pH. These applications include early-stage detectors for some cancers, agents in drug discovery, and contrast agents for Magnetic Resonance Imaging due to their suitable bioluminescent properties. This synthesis was performed in a 14-step route that was designed to allow various pendant arms and substituents to be attached at various stages. For this specific ligand, two tertiary butyl ester groups are located on either side along with the aspartic acid form of these ester groups located on the bottom. A variation of purification techniques were explored based upon the different products’ behaviour including silica gel/alumina columns, simple extractions, and an inverse-phase auto-purification system. Along this synthesis, certain problems arouse such as the pre-mature hydrolysis of the ester groups during purification as well as the removal of different protecting groups such as THP and nosyl. Some reaction conditions were changed from the original schematic provided to allow for such protection steps to be skipped or that some products are now commercially available, thus decreasing the overall number of steps from fourteen to ten. As the macrocycle has not yet been completed, yield cannot be stated but this work is currently in progress.

Advancements in magnetic resonance imaging: Synthesis of a bromo-functionalized macrocyclic pyrinophane ligand

255th National Meeting (2018)

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