Synthesis of 6-[¹⁸F]fluoro-PBR28, a novel radiotracer for imaging the TSPO 18 kDa with PET.

Basic Information

ID: ALA1817668

Journal: Bioorg Med Chem Lett

Title: Synthesis of 6-[¹⁸F]fluoro-PBR28, a novel radiotracer for imaging the TSPO 18 kDa with PET.

Authors: Damont A, Boisgard R, Kuhnast B, Lemée F, Raggiri G, Scarf AM, Da Pozzo E, Selleri S, Martini C, Tavitian B, Kassiou M, Dollé F.

Abstract: 6-Fluoro-PBR28 (N-(6-fluoro-4-phenoxypyridin-3-yl)-N-(2-methoxybenzyl)acetamide), a fluorinated analogue of the recently developed TSPO 18 kDa ligand PBR28, was synthesized and labelled with fluorine-18. 6-Fluoro-PBR28 and its 6-chloro/6-bromo counterparts were synthesized in six chemical steps and obtained in 16%, 10% and 19% overall yields, respectively. Labelling with fluorine-18 was performed in one single step (chlorine/bromine-for-fluorine heteroaromatic substitution) using a Zymate-XP robotic system affording HPLC-purified, ready-to-inject, 6-[(18)F]fluoro-PBR28 (>95% radiochemically pure). Non-decay-corrected overall yields were 9-10% and specific radioactivities ranged from 74 to 148 GBq/μmol. In vitro binding experiments, dynamic μPET studies performed in a rat model of acute neuroinflammation (unilaterally, AMPA-induced, striatum-lesioned rats) and ex vivo autoradiography on the same model demonstrated the potential of 6-[(18)F]fluoro-PBR28 to image the TSPO 18 kDa using PET.

CiteXplore: 21741237

DOI: 10.1016/j.bmcl.2011.06.048

Patent ID: