Direct Synthesis of Tricarbonyl(cyclopentadienyl)rhenium and Tricarbonyl(cyclopentadienyl)technetium Units from Ferrocenyl Moieties − Preparation of 17α‐Ethynylestradiol Derivatives Bearing a Tricarbonyl(cyclopentadienyl)technetium Group

Abstract

Abstract The preparation of new tricarbonyl(cyclopentadienyl)rhenium and tricarbonyl(cyclopentadienyl)technetium derivatives is described. The approach used was applied to a cold target model, 17α‐ethynylestradiol substituted at the 17α position by a ketotricarbonyl(cyclopentadienyl)rhenium group. The novel organometallic reaction applied here, when extended to potential radiopharmaceuticals, consists of a cyclopentadienyl‐ligand transfer between ketoferrocenes and fac ‐[ 99m Tc(H 2 O) 3 (CO) 3 ] + in a water/DMSO 1:1 mixture. This reaction lead to the synthesis of a new estradiol derivative, labeled with 99m Tc. The synthesis of another product was performed by using [ 99 TcCl 3 (CO) 3 ] 2− as the Tc precursor and its X‐ray crystal structure was determined. In each case high yields were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)