A series of xanomeline analogs were synthesized and evaluated for binding at the M1 muscarinic acetylcholine receptor (M1 receptor). Specifically, compounds that substitute the O-hexyl chain of xanomeline with polar, ionizable, or conformationally restricted moieties were assessed for their ability to bind to the M1 receptor in a wash-resistant manner (persistent binding). From our screen, several novel ligands that persistently bind to the ...