Selective activation of the M
1 muscarinic receptor via positive allosteric modulation represents an approach to treat the cognitive decline in patients with Alzheimer's disease. A series of amides were examined as a replacement for the carboxylic acid moiety in a class of quinolizidinone carboxylic acid M
1 muscarinic receptor positive allosteric modulators, and leading pyran
4o and cyclohexane
5c were found to possess good potency and in vivo efficacy.
Keywords:
carboxylic acid surrogates; quinolizidinone; positive allosteric modulators