The sequential syntheses of [76Br]FBAU 3′,5′-dibenzoate and [76Br]FBAU

✍ Scribed by Chih-Hao K. Kao; Mark B. Sassaman; Lawrence P. Szajek; Ying Ma; Atsuo Waki; William C. Eckelman

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 126 KB
• Volume: 44
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.515

✦ Synopsis

Abstract

Thymidine analogs labeled with positron emitting radionuclides are potential proliferation markers for positron emission tomography (PET). Bromine‐76 (T~1/2~=16.2 h) is our choice of radionuclide, because it allows for maximal DNA incorporation of the tracer. Following the literature descriptions, ^76^Br was produced using the ^75^As (^3^He, 2n) ^76^Br reaction. We then recovered ^76^Br from the target in the form of [^76^Br]NH~4~Br with a yield of 60±12% (n=32). Peracetic acid was used as the oxidant for electrophilic bromodestannylation to prepare [^76^Br]FBAU 3′,5′‐dibenzoate (71.2±12.1%, RCY) and a basic hydrolysis of the dibenzoate then yielded [^76^Br]FBAU. The yield of the hydrolysis reaction was 53.1±9.2% when heated at 100°C for 15 min or quantitative (decay corrected) when left at room temperature overnight. The sequential synthesis of [^76^Br]FBAU 3′,5′‐dibenzoate and [^76^Br]FBAU allowed us to perform a side‐by‐side comparison of their metabolic stabilities. While [^76^Br]FBAU 3′,5′‐dibenzoate was hydrolyzed to [^76^Br]FBAU within 10 minutes by hepatocyte at 37°C, [^76^Br]FBAU was stable and no [^76^Br]Br^−^ was released from either radiopharmaceutical. Both compounds are potential proliferation markers for PET. Copyright © 2001 John Wiley & Sons, Ltd.