BAY 73-6691

BAY 73-6691

Clinical data
ATC code	None
Identifiers
IUPAC name 1-(2-Chlorophenyl)-6-[(2R)-3,3,3-trifluoro-2-methylpropyl]-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidine-4-one
CAS Number	794568-92-6 Y
PubChem CID	16078952
ChemSpider	21171546 Y
ChEMBL	CHEMBL1513993
ECHA InfoCard	100.150.853
Chemical and physical data
Formula	C15H12ClF3N4O
Molar mass	356.730 g/mol
3D model (JSmol)	Interactive image
SMILES C[C@H](CC1=NC(=O)C2=CNN(C2=N1)C3=CC=CC=C3Cl)C(F)(F)F
InChI InChI=1S/C15H12ClF3N4O/c1-8(15(17,18)19)6-12-21-13-9(14(24)22-12)7-20-23(13)11-5-3-2-4-10(11)16/h2-5,7-8H,6H2,1H3,(H,21,22,24)/t8-/m1/s1 Y Key:FFPXPXOAFQCNBS-MRVPVSSYSA-N Y
Y (what is this?)

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 PDE9A subtype. The PDE9A 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 PDE9A 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, PDE9A 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.