Preparation of cyclopentadienyl tricarbonyl technetium‐94m complexes

Abstract

Cyclopentadienyltricarbonyl complexes with technetium‐94m have been prepared by two methods and were characterized by comparison to rhenium analogues.

Rhenium(I) and Technetium(I) Tricarbonyl Complexes with [NSO]‐Type Chelators: Synthesis, Structural Characterization, and Radiochemistry

“…[7] A variety of NSO chelators has been developed that include an amine or aromatic N atom, a thioether S atom, and a carboxylate group O atom, which have been established as suitable systems for the 99m Tc/[Re(CO) 3 ] + core. [5][6][7][8][9][10][11][12][13][14][15] Interesting [M(CO) 3 ] + coordination chemistry has been reported with NSO ligands that offer more than one possible mode of complexation, such as [(2-pyridinyl)methyl]-S-cysteine, S-carboxymethyl-l-cysteine, and [2-(2-pyridinyl)ethyl]-S-homocysteine derivatives. [5][6][7][8][9][10][11][12][13][14][15] Interesting [M(CO) 3 ] + coordination chemistry has been reported with NSO ligands that offer more than one possible mode of complexation, such as [(2-pyridinyl)methyl]-S-cysteine, S-carboxymethyl-l-cysteine, and [2-(2-pyridinyl)ethyl]-S-homocysteine derivatives.…”

99m Tc-labeled estradiol as an estrogen receptor probe: Preparation and preclinical evaluation

“…It does not alter biodistribution or tumor uptake patterns [21]. In addition, unlike other studies highlighting the difficulty of preparing 99m Tc-labeled derivatives with high specific activity or yields [9,11], 99m Tc-DTPA-estradiol was prepared easily, with a satisfactory yield and labeling efficiency. The…”

“…Lipophilic compounds are usually characterized by slow elimination from the blood pool, resulting in high accumulation within extensively-perfused organs such as the liver and spleen [8,9,11].Additionally, steroid hormones (including estrogen) have been identified as stimulators of the reticuloendothelial system [28,29], suggesting that phagocytosis within the liver and spleen may be another possible contributor towards such a phenomenon. We encountered similar problems.…”

“…The most successful 18 F-labeled estrogen derivative, 16α-18 F-17β-estradiol ( 18 F-FES), has been evaluated clinically, with promising results reported for prediction of treatment response to anti-estrogen drugs such as tamoxifen [7]. Subsequent studies have been directed at developing methods for labeling estrogen imaging agents with 99m Tc for single-photon emission-computed tomography (SPECT) [8,9].…”

“…The complex chemistry involved in the radiosynthesis of these compounds to obtain high yields and purities has further hampered their development [9][10][11].…”