Discovery and optimization of a novel, selective and brain penetrant M1 positive allosteric modulator (PAM): The development of ML169, an MLPCN probe

This Letter describes a chemical lead optimization campaign directed at VU0108370, a weak M-1 PAM hit with a novel chemical scaffold from a functional HTS screen within the MLPCN. An iterative parallel synthesis approach rapidly established SAR for this series and afforded VU0405652 (ML169), a potent, selective and brain penetrant M-1 PAM with an in vitro profile comparable to the prototypical M-1 PAM, BQCA, but with an improved brain to plasma ratio. (C) 2010 Elsevier Ltd. All rights reserved.