Evaluation of aromatic radiobromination by nucleophilic substitution using diaryliodonium salt precursors [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 541.36 Thermochemistry and thermodynamics
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2017
• Mô tả vật lý: Size: p. 450-456 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 260568
• Chủ đề: 1. 38 radiation chemistry, radiochemistry, and nuclear chemistry; 2. 60 applied life sciences; 3. Auger electron radiation; 4. Biochemistry & molecular biology; 5. Bromine-76; 6. Bromine-77; 7. Chemistry; 8. Diaryliodonium salts; 9. Et al; 10. Labeling methods; 11. Pharmacology & pharmacy

Tóm tắt

 Radiobromine-labeled compounds can be used for positron emission tomography (PET) imaging (ie, <
 sup>
 76<
 /sup>
 Br) and for radiation therapy (ie, <
 sup>
 77<
 /sup>
 Br). However, the commonly used electrophilic substitution reaction using no-carrier-added radiobromide does not always afford the desired product due to the high reactivity of the brominating intermediate. A nucleophilic substitution by bromide, such as radiobromination of iodonium precursors, provides an alternative route for the synthesis of bromo-radiopharmaceuticals. The applicability of aromatic radiobromination by nucleophilic substitution using diaryliodonium salt precursors was evaluated using iodonium model compounds and [<
 sup>
 76<
 /sup>
 Br]/[<
 sup>
 77<
 /sup>
 Br]bromide. Radiobromination was observed under all conditions tested, in up to quantitative yields. A QMA cartridge treatment method and a base-free method have been developed, and no extra base is needed for either methods. The base-free conditions are mild and afford much cleaner reactions. Up to 20% water is tolerated in the reactions without reducing the radiochemical yields. No-carrier-added and carrier-added reactions afforded similar results. 4-Bromobenzaldehyde and 4-bromobenzoate have been radiosynthesized reliably and in good yields. Finally, these results indicate that this method is robust and efficient and thus will provide a route for radiobromination of electron-deficient arenes and an alternative route for the synthesis of bromo-radiopharmaceuticals for biological evaluations.