Bromination from the macroscopic level to the tracer radiochemical level: (76)Br radiolabeling of aromatic compounds via electrophilic substitution Journal Article
| Authors: | Zhou, D.; Zhou, H.; Jenks, C. C.; Lewis, J. S.; Katzenellenbogen, J. A.; Welch, M. J. |
| Article Title: | Bromination from the macroscopic level to the tracer radiochemical level: (76)Br radiolabeling of aromatic compounds via electrophilic substitution |
| Abstract: | No-carrier-added (NCA) (76)Br labeling of 4-(5-acetoxy-7- bromobenzoxazol-2-yl)phenyl acetate, a diacetate-protected estrogen-receptor beta (ERβ) selective ligand, was carried out successfully using [ (76)Br]bromide ion. The labeling was achieved via oxidative electrophilic destannylation of an organotin precursor molecule by modification of the leaving group (from Bu(3)Sn to Me(3)Sn) and the addition of methanol to the reaction mixture. The differences between the oxidative bromination reaction under small-scale macroscopic vs tracer level radiochemical conditions were explored in terms of effective brominating agents, which depend greatly on the nature of the solvent during the radiochemical bromination, and the potential interference by trace levels of highly reactive impurities in the reaction that compete for the desired bromination at the NCA level. Our observations, and our development of experimental protocols for successful radiobromination at the tracer NCA-scale, should be applicable to the synthesis of other radiobromine-labeled organic compounds of potential interest as PET radiopharmaceuticals and radiotherapy agents. © 2009 American Chemical Society. |
| Keywords: | unclassified drug; positron emission tomography; oxidants; drug synthesis; isotope labeling; radioactivity; radiopharmaceutical agent; radioactive tracers; hydrogen peroxide; water; oxidation-reduction; staining and labeling; radiochemistry; solvent; solvents; 4 (5 acetoxy 7 bromobenzoxazol 2 yl)phenyl acetate br 76; aromatic compound; bromine 76; electrophile; methanol; peracetic acid; bromination; bromine radioisotopes; halogenation; organic chemicals; trialkyltin compounds |
| Journal Title: | Bioconjugate Chemistry |
| Volume: | 20 |
| Issue: | 4 |
| ISSN: | 1043-1802 |
| Publisher: | American Chemical Society |
| Date Published: | 2009-04-15 |
| Start Page: | 808 |
| End Page: | 816 |
| Language: | English |
| DOI: | 10.1021/bc800313c |
| PUBMED: | 19260733 |
| PROVIDER: | scopus |
| PMCID: | PMC2743097 |
| DOI/URL: | |
| Notes: | --- - "Cited By (since 1996): 2" - "Export Date: 30 November 2010" - "CODEN: BCCHE" - "Source: Scopus" |
