Synthesis and characterization of [99mTc]metomidate as the tricarbonyl‐conjugate

Abstract Functionalized metomidate was labelled with the [ 99m Tc]tricarbonyl‐complex in high yield. With carrier amounts of Tc‐99 the analogous [ 99 Tc]tricarbonyl‐BiPy‐MTO‐conjugate was obtained, showing an identical retention time, however, conjugate formation was not quantitative. When the [Re]tribromo‐tricarbonyl‐ligand was reacted with the BiPy‐MTO‐precursor, the reaction parameters had to be optimized for conjugate formation. Based on high adrenocortical binding to adrenal tissue slices, it is expected that the radiotracer will also localize in the adrenal in‐vivo.