Rhenium and technetium complexes bearing quinazoline derivatives: progress towards a 99mTc biomarker for EGFR-TK imaging.

The quinazoline derivatives (3-chloro-4-fluorophenyl)quinazoline-4,6-diamine (2) and (3-bromophenyl)quinazoline-4,6-diamine (3) were labelled with (99m)Tc using the "4 + 1" mixed-ligand system [Tc(NS3)(CN-R)] and the tricarbonyl moiety fac-[Tc(CO)3]+. In the "4 + 1" approach the technetium(iii) is stabilized by a monodentate isocyanide bearing a quinazoline fragment (L1,L2 ) and by the tetradentate tripodal ligand tris(2-mercaptoethyl)-amine (NS3). In the "4 + 1" approach, 99mTc-labelling was performed in a two-step procedure, the complexes [Tc(NS3)(L1)] (7a) and [Tc(NS3)(L2)] (8a) being obtained in about 50-70% yield.

Convenient route leading to neutral fac-M(CO)3(NNO) complexes (M = Re, 99mTc) coupled to amine pharmacophores.

The synthesis and characterization of three neutral tricarbonyl fac-M(CO)3(NNO) (M = Re, (99m)Tc) complexes based on the picolylamine N,N-diacetic acid (PADA) ligand is reported. One of the two carboxylate groups of the PADA ligand is efficiently and conveniently derivatized with an amine nucleophile through the use of the PADA anhydride. In this work, aniline, benzylamine and pyrrolidine were used as model amine nucleophiles.

Synthesis and characterization of novel "3 + 2" oxorhenium complexes, ReO[SNO][NN].

The present paper deals with the synthesis and structural characterization of novel neutral oxorhenium(V) complexes of the general formula ReO[SNO][NN]. The simultaneous action of the tridentate SNO ligand, N-(2-mercaptoacetyl)glycine (1), and the bidentate NN ligand, N-phenylpyridine-2-aldimine (2), on ReOCl3(PPh3)2 leads to the formation of two isomers 4a and 4b of the general formula ReO[SNO][NN], as a result of the different orientations of the NN ligand. In both cases, the SNO donor atoms of the tridentate ligand occupy the three positions in the equatorial plane of the distorted octahedron, whereas the oxo group is always directed toward one of the apical positions.