Synthesis and SAR of analogues of the M1 allosteric agonist TBPB. Part I: Exploration of alternative benzyl and privileged structure moieties

This Letter describes the first account of the synthesis and SAR, developed through an iterative analogue library approach, of analogues of the highly selective M1 allosteric agonist TBPB. With slight structural changes, mAChR selectivity was maintained, but the degree of partial M1 agonism varied considerably.