SYNTHESIS AND MOLECULAR-STRUCTURE OF A RHENIUM COMPLEX DERIVED FROM 8-ALPHA-AMINO-6-METHYL-ERGOLINE

Current research in radiopharmaceutical chemistry is aimed at the desi gn of technetium-based receptor-binding radiotracers because of the ex cellent nuclide properties of the isotope (TC)-T-99m. Tc tracers and t he corresponding complexes of rhenium, as the inactive surrogate of Tc , are required to imitate organic agonists or antagonists of the recep tor. We have started studies with ergolines, which are known to be dop amine substitutes. The present report deals with the functionalization of 8 alpha-amino-6-methyl-ergoline (2) with a 2-mercaptoacetyl group, and the subsequent synthesis of the first rhenium complex containing a pendent ergoline moiety [Re-O(SSS)(RS)] (HSSSH = HS-CH2CH2-S-CH2CH2- SH and RSH = 8 lpha-amino-N-(2-mercaptoacetyl)-6-methyl-ergoline) (4). The molecular structure of the rhenium complex was determined by X-ra y crystal structure analysis.