Detailed radiosynthesis of [ 18 F]mG4P027 as a positron emission tomography radiotracer for mGluR4.

We report here the detailed radiosynthesis of [ 18 F]mG4P027, a metabotropic glutamate receptor 4 (mGluR4) PET radiotracer, which showed superior properties to the currently reported mGluR4 radiotracers. The radiosynthesis in the automated system has been challenging, therefore we disclose here the major limiting factors for the synthesis via step-by-step examination. And we hope this thorough study will help its automation for human use in the future.