Kinetics and mechanism of the nucleophilic exchange reaction of iodide‐131 with 15‐(para‐iodo‐phenyl) pentadecanoic acid

El-Wetery, A. S.; El-Azoney, Kh. M.; Raieh, M.

doi:10.1002/(sici)1099-1344(199712)39:12<987::aid-jlcr44>3.0.co;2-#

Cited by 5 publications

(1 citation statement)

References 20 publications

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“…3a,b. Although ethanol has been selected in the labeling of several pharmaceutical compounds such as p-iodo-phenyl pentadecanoic acid by radioiodide [12], in our case of the labeling of 3-IPP by radioiodide, the yield is relatively poor and reaches the saturation value of 30% at 60 • C within 30 min. By raising the reaction temperature to 160 • C, the labeling yield slightly increased to 48% within a short time (10 min) as shown in Fig.…”

Section: Effect Of Temperature On the Isotopic Exchange Between 3-ippmentioning

confidence: 99%

Radioiodination of 3-iodo-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine via isotopic exchange reaction

El-Azony¹,

El-Mohty

Deeb

et al. 2010

Radiochimica Acta

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Radioiodination of 3-iodo-4,5-diphenyl-1H-pyrazolo [3,4-c]pyridazine (3-IPP) with iodine-125 was performed via 125 I for I isotopic exchange reaction in different organic media such as acetone, dimethyl formamide (DMF), ethanol and ethyl acetate. The reaction temperature has a great effect on the labeling yield in case of DMF or ethanol as a reaction medium. The activation energies were calculated to be 4.6 kcal/mol (19.3 kJ/mol) in case of DMF as a reaction medium without phase transfer catalyst and 3.3 kcal/mol (13.8 kJ/mol) in the presence of tetrabutyl ammonium bromide (TBAB) as a phase transfer catalyst. These values are low compared with the calculated activation energy in the case of ethanol as a reaction medium (9.2 kcal/mol (38.5 kJ/mol)). The maximum radiochemical yield of 3-125 IPP (92%) was obtained by using 20 µL of Na 125 I (7.4 MBq (200 µCi)) in the reaction flask and then adding the mixture of 150 µL of 3-IPP (1.88 mM) and 50 µL TBAB (3 mM) at 160 • C within 5 min. The labeled product was purified by means of high pressure liquid chromatography (HPLC) to give a specific activity of 272 MBq/mmol for 3-125 IPP.

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Section: Effect Of Temperature On the Isotopic Exchange Between 3-ippmentioning

confidence: 99%

Radioiodination of 3-iodo-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine via isotopic exchange reaction

El-Azony¹,

El-Mohty

Deeb

et al. 2010

Radiochimica Acta

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Evaluation of the reaction parameters and thermodynamics of the iodide-exchange preparation of radioiodinated 15-(p-iodophenyl) pentadecanoic acid by both solid phase and solution methods

Farah

1998

J Label Compd Radiopharm

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Two isotopic exchange procedures are described for the labelling of 15‐(p‐iodophenyl) pentadecanoic acid with radioiodine in the presence of ammonium sulphate and cuprous chloride as catalysts. The methods afforded regioselective and high specific activity products with radiochemical yields of 92% and 85% within relatively short reaction times. High pressure liquid chromatographic separation resulted in high radiochemically pure product suitable for medical application. Kinetic studies revealed second order iodine–iodine exchange reactions with an activation energy of 13.7 Kcal/mole for the solid state radioiodination with ammonium sulphate and 15.3 Kcal/mole for the copper catalyzed exchange reaction. © 1998 John Wiley & Sons, Ltd.

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Radiohalogen incorporation into organic systems

Bolton

2002

Labelled Comp Radiopharmac

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SummaryThis Review reports the more recent applications of radiohalogen labelling in organic compounds. Modern synthetic methods place more emphasis upon substitution at specific sites. Electrophilic substitution, especially at aromatic carbon atoms, involves displacement of halogen or of metals rather than the earlier popular halogen-deprotiation processes. Nucleophilic displacement, at either aliphatic or aromatic sites, has also become widespread since it may be made more selective by the inclusion of appropriate activating groups or suitable displaced groups. Microwave and thermally induced methods are both reported with a critical assessment of the value of each process.

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Kinetics and mechanism of the nucleophilic exchange reaction of iodide‐131 with 15‐(para‐iodo‐phenyl) pentadecanoic acid

Cited by 5 publications

References 20 publications

Radioiodination of 3-iodo-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine via isotopic exchange reaction

Radioiodination of 3-iodo-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine via isotopic exchange reaction

Evaluation of the reaction parameters and thermodynamics of the iodide-exchange preparation of radioiodinated 15-(p-iodophenyl) pentadecanoic acid by both solid phase and solution methods

Radiohalogen incorporation into organic systems

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