An updated synthesis of N 1 ′‐([ 11 C]methyl)naltrindole for positron emission tomography imaging of the delta opioid receptor

摘要: A new method for the synthesis of highly selective delta opioid receptor (DOR) antagonist radiotracer N1 '-([11 C]methyl)naltrindole ([11 C]MeNTI) is described. The original required hydrogenation a benzyl protecting group after 11 C-labeling, which challenging in modern radiochemistry laboratories that tend to be heavily automated and operate according current good manufacturing practice. To address this challenge, we describe development novel MeNTI precursor bearing methoxymethyl acetal (MOM) group, easily removed with HCl, employ it an updated [11 C]MeNTI. fully validated clinical use. total time 45 min provides C]MeNTI activity yield (49 ± 8 mCi), molar (3,926 326 Ci/mmol) radiochemical purity (97% 2%).