Synthesis of N-tert-butyl-α-(4-[18F]fluorophenyl)-nitrone ([18F]FPBN) for in vivo detection of free radicals

✍ Scribed by G. Bormans; M. R. Kilbourn

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: French
• Weight: 373 KB
• Volume: 36
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.2580360202

✦ Synopsis

Abstract

We have synthesized the fluorine‐18 labeled derivative of N‐tert‐butyl‐α‐phenylnitrone (PBN), a free radical spin trapping agent widely used with electron spin resonance (ESR). N‐tert‐Butyl‐α‐(4‐[^18^F]fluorophenyl)‐nitrone ([^18^F]FPBN) could be prepared with low radiochemical yield (3% decay corrected) by the direct aromatic nucleophilic substitution of N‐tert‐butyl‐α‐(4‐nitrophenyl)nitrone with [^18^F]fluoride. An alternate two step synthesis route consisted of the nucleophilic [^18^F]fluoride substitution of 4‐N, N, N‐trimethylammoniumbenzaldehyde triflate to yield 4‐[^18^F]fluorobenzaldehyde, which was distilled into a vial containing N‐tert‐butyl‐hydroxylamine in 2N NaOH. 4‐[^18^F]Fluorobenzaldehyde readily reacted with the hydroxylamine to form [^18^F]FPBN. [^18^F]FPBN was obtained in overall decay corrected yields of 24% in a total synthesis time < 45 min. and was suitable for further applications in in vivo studies of free radicals.