Jean-Claude Pierrard, Jean Rimbault, Michel Aplincourt, Soizic Le Greneur and Marc Port
The new total synthesis in four steps of the compound P1041, a high molecular mass ligand (MW 6.32 kDa) derived from dota, is reported. Study of the systems P1041/Na+ and P1041/Gd3+ led to the determination of the stability constants corresponding to the species Na(P1041)Hh (h = 0, 2 or 4) and to the complexes Gd(P1041)Hh (h = 0, 2, 3, 4 or 5). The complexing ability of P1041 towards Gd3+ is compared with those of dota and tetracarboxylated dota. At physiological pH = 7.4, the very stable species Gd(P1041)H4− of this rapid clearance blood pool agent is predominant.