Identification of positron emission tomography ligands for NPY Y5 receptors in the brain
A series of trans-3-oxospiro[(aza)isobenzofuran-1(3H),1′-cyclohexane]-4′-carboxamide derivatives were synthesized and profiled for NPY Y5 binding affinity, brain and CSF penetrability in rats, and susceptibility to human and mouse P-glycoprotein transporters in order to develop a PET ligand. Compound 12b exhibited an acceptable profile for a PET ligand, and [11C]12b was successfully utilized in clinical settings as a Y5 PET ligand.