Automated one‐step radiosynthesis of the CB1 receptor imaging agent [18F]MK‐9470. (25th August 2014)

• Record Type: Journal Article
• Authors: Thomae, David; Morley, Thomas J.; Hamill, Terence; Carroll, Vincent M.; Papin, Caroline; Twardy, Nicole M.; Lee, H. Sharon; Hargreaves, Richard; Baldwin, Ronald M.; Tamagnan, Gilles; Alagille, David
• Is Part Of: Journal of labelled compounds & radiopharmaceuticals. Volume 57:Number 10(2014)
• Page Start: 611
• Page End: 614
• Publication Date: 2014-08-25
• Subjects: Tracers (Chemistry) -- Periodicals; Radiopharmaceuticals -- Periodicals; 615.8424
• DOI: 10.1002/jlcr.3219
• Languages: English
• ISSNs: 0362-4803

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The fluorine‐18‐labeled positron emission tomography (PET) radiotracer [¹⁸F]MK‐9470 is a selective, high affinity inverse agonist that has been used to image the cannabinoid receptor type 1 in human brain in healthy and disease states. This report describes a simplified, one‐step [¹⁸F]radiofluorination approach using a GE TRACERlab FX_FN module for the routine production of this tracer. The one‐step synthesis, by [¹⁸F]fluoride displacement of a primary tosylate precursor, gives a six‐fold increase in yield over the previous two‐step method employing <italic>O</italic>‐alkylation of a phenol precursor with 1, 2‐[¹⁸F]fluorobromoethane. The average radiochemical yield of [¹⁸F]MK‐9470 using the one‐step method was 30.3 ± 11.7% (<italic>n</italic> = 12), with specific activity in excess of 6 Ci/µmol and radiochemical purity of 97.2 ± 1.5% (<italic>n</italic> = 12), in less than 60 min. This simplified, high yielding, automated process was validated for routine GMP production of [¹⁸F]MK‐9470 for clinical studies.</p> </abstract>