Rapid and efficient radiosynthesis of [123I]I-PK11195, a single photon emission computed tomography tracer for peripheral benzodiazepine receptors

Synthesis and Characterization of Iodinated Tetrahydroquinolines Targeting the G Protein-Coupled Estrogen Receptor GPR30

“…The iodide 3 exhibited favorable characteristics including reduced lipophilicity and high selectivity as a GPR30 agonist; however, the inaccessibility of the tributylstannyl precursor through the synthetic routes investigated prevented further evaluation of the radioiodinated compound. It may be possible to incorporate the less sterically-demanding trimethylstannyl group, which could serve as a precursor for I-125 labeling to yield this promising agent 44. We have previously described 99m Tc-labeled 17β-estradiol derivatives that incorporate pyridin-2-yl-hydrazine chelates for SPECT imaging applications 45,46.…”

A one-pot radioiodination of aryl amines via stable diazonium salts: preparation of 125I-imaging agents

“…1a). 2,3a While this method generates SPECT imaging agents with high specific activity and radiochemical purity, 4 there are obvious toxicity risks associated with the generation of clinical tracers from organotin compounds. In addition, the unstable nature of organotin compounds prevents long-term storage and can result in unreliable radioiodination.…”

Nickel‐Mediated Radioiodination of Aryl and Heteroaryl Bromides: Rapid Synthesis of Tracers for SPECT Imaging

“…[13] However, these initial results from the development of a radioiodination reaction showed that when the iodide ion, in this case [ 125 I]-NaI, is the limiting reagent, the equilibrium of halogen exchange is inhibited by the presence of an excess of bromide ions. While the temperature required for this transformation is higher than that for other radioiodination methods, [6,7] analysis by radio-HPLC showed clean reactions with no side products from processes such as S N Ar reactions (see Figure 1). While nickel powder gave low conversion because of poor solubility, the reaction with bis(1,5-cyclooctadiene)nickel(0) was successful.…”

“…In particular, the use of single photon emission computed tomography (SPECT) with radioiodinated probes has found widespread application in biological research ( 125 I) and diagnostic imaging ( 123 I), specifically with diseases associated with the central nervous system. [6] However, there are issues with this approach, such as toxicity concerns associated with the potential of organotin residues in clinical preparations of radioiodinated molecular imaging agents. [1][2][3][4][5] The most commonly used approach is a two-step procedure that involves a palladium(0)-catalyzed stannylation of a halogenated arene or alkene followed by an oxidative iodo-destannylation (Scheme 1 a).…”