Application of the Ugi four-component reaction to the synthesis of ditopic bifunctional chelating agents.

摘要: The Ugi four-component reaction (Ugi 4CR) was exploited for the first time to obtain in a single synthetic step bifunctional ditopic chelators by using DOTA monoamide (DOTAMA) derivatives as amino and acid components. A number of systems which two DOTAMA units are connected central α-acylaminoamide group were synthesized reacting different aldehydes, isocyanides chelates containing functionalities. Variation components allows insertion another functional into skeleton further conjugation biomolecules. optimal conditions found methanol solvent ultrasound irradiation at power 60 W (20 kHz) 3 h. Gd(III) complexes dimeric ligands L1 L2 (bearing cyclohexyl ring an octadecyl chain on moiety, respectively) fully characterized aqueous media relaxometric techniques with varying temperature magnetic field strength. relaxivity Gd2L1 Gd2L2 (in aggregated form), 20 MHz 310 K, 5.6 20.0 mM−1 s−1, respectively. enhanced value indicates that this lipophilic complex forms micelles concentrations <0.1 mM. Finally, binding human serum albumin (HSA) investigated proton relaxometry, affinity constant macromolecular adduct (rb1p = 38.1 s−1; K) derived.