Design and Synthesis of Novel Muscarinic Agonists Containing the 1,2,4- Triazine Ring as an Ester Bioisostere.

Abstract Replacement of the ester group in methyl quinuclidine-3-car☐ylate1 with a 1,2,4-triazine ring afforded the high affinity muscarinic partial agonist6a. Analogues7a,7b and7d which incorporate the 1-azabicyclo[2.2.1]heptane ring also display high affinity for muscarinic receptors.