No-carrier-added (4-fluoro-3-[131I]iodobenzyl)guanidine and (3-[211At]astato-4-fluorobenzyl)guanidine.


Journal Article

With 3-bromo-4-fluorotoluene as starting material, [4-fluoro-3-(trimethylsilyl)benzyl]guanidine was prepared in five steps in 1.5% overall yield. Radioiodination of this silicon precursor using N-chlorosuccinimide in trifluoroacetic acid at room temperature for 5 min gave (4-fluoro-3-[131I]-iodobenzyl)guanidine ([131I]FIBG) in 50-60% radiochemical yield. A byproduct which had a retention time in two HPLC systems similar to that of (m-iodobenzyl)guanidine (MIBG) was formed in about 30% yield. [131I]FIBG was stable up to 3 h under these conditions of iodination, indicating that the byproduct is not generated as a result of [131I]FIBG degradation. Using hydrogen peroxide as the oxidant in aqueous medium and a reaction time of 30 min at 50 degrees C, yields of [131I]FIBG could be increased to 75-80%, with less than 7% of the byproduct formed under these conditions. Astatination of the silicon precursor using N-chlorosuccinimide in trifluoroacetic acid at 70 degrees C gave 65-70% radiochemical yield of (3-[211At]astato-4-fluorobenzyl)guanidine ([211At]AFBG) in 10-15 min; about 17% of the byproduct formation was seen. Astatination of the silicon precursor under aqueous conditions using hydrogen peroxide was not successful.

Full Text

Duke Authors

Cited Authors

  • Vaidyanathan, G; Affleck, DJ; Zalutsky, MR

Published Date

  • January 1, 1996

Published In

Volume / Issue

  • 7 / 1

Start / End Page

  • 102 - 107

PubMed ID

  • 8741997

Pubmed Central ID

  • 8741997

International Standard Serial Number (ISSN)

  • 1043-1802

Digital Object Identifier (DOI)

  • 10.1021/bc950078i


  • eng

Conference Location

  • United States