Development of N-Methyl-(2-arylquinolin-4-yl)oxypropanamides as Leads to PET Radioligands for Translocator Protein (18 kDa)
摘要:
Translocator protein (18 kDa), known as TSPO, is a recognized biomarker of neuroinflammation. Radioligands with PET accurately quantify TSPO in neuroinflammatory conditions. However, the existence of three human TSPO genotypes that show differential affinity to almost all useful TSPO PET radioligands hampers such studies. There is an unmet need for genotype-insensitive, high-affinity, and moderately lipophilic TSPO ligands that may serve as leads for PET radioligand development. To address this need, we varied the known high-affinity TSPO ligand (l)-N,N-diethyl-2-methyl-3-(2-phenylquinolin-4-yl)propanamide in its aryl scaffold, side chain tether, and pendant substituted amido group while retaining an N-methyl group as a site for labeling with carbon-11. From this effort, oxygen-tethered N-methyl-aryloxypropanamides emerged as new high-affinity TSPO ligands with attenuated lipophilicity, including one example with attractive properties for PET radioligand development, namely N-methyl-N-phenyl-2-{[2-(pyridin-2-yl)quinolin-4-yl]oxy}propanamide (22a; rat K-i = 0.10 nM; human TSPO genotypes K-i = 1.4 nM; clogD = 4.18).
Copper-Catalyzed Synthesis of Azaspirocyclohexadienones from α-Azido-<i>N</i>-arylamides under an Oxygen Atmosphere
作者:Shunsuke Chiba、Line Zhang、Jian-Yuan Lee
DOI:10.1021/ja1027327
日期:2010.6.2
copper-catalyzed reaction of alpha-azido-N-arylamides was found to proceed under an oxygen atmosphere to afford azaspirocyclohexadienones. The present transformation is carried out by a sequence of denitrogenative formation of iminyl copper species from alpha-azido-N-arylamides and their imino-cupration with an intramolecular benzene ring on the amido nitrogen followed by consecutive formation of C=O bonds. The