BAY 73-6691

BAY 73-6691

File:BAY73-6691 structure.png
Systematic (IUPAC) name
1-(2-chlorophenyl)-6-[(2R)-3,3,3-trifluoro-2-methylpropyl]-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidine-4-one
Identifiers
CAS Number	794568-92-6
PubChem	CID 16078952
Chemical data
Formula	C15H12ClF3N4O
Molar mass	356.730 g/mol[[]]

BAY 73-6691 is a drug developed by Bayer for the treatment of Alzheimer's disease. It was the first compound developed that acts as a phosphodiesterase inhibitor selective for the PDE_9A subtype. The PDE_9A enzyme is expressed primarily in the brain, with high concentrations in the cerebellum, neocortex, striatum, and hippocampus, and acts to limit the cGMP-mediated signal transduction which occurs following glutamate binding to NMDA receptors. Consequently selective PDE_9A inhibitors were predicted to prolong intracellular responses to glutamate and enhance glutamate signalling, and since this process is known to be involved in learning and memory, PDE_9A inhibitors should have a nootropic effect and may be useful in the treatment of Alzheimer's.

Animal studies have confirmed these expectations, and BAY 73-6691 has been shown to improve learning and memory in rats. As the first selective PDE_9A inhibitor to be developed, it is also widely used in research into the function of this enzyme subtype. However pre-clinical research is at an early stage and it is not yet known whether BAY 73-6691 will prove suitable to progress to human trials, or if it will remain merely a laboratory research tool.