Design, synthesis and biological activity of pyrazolo[1,5-a]pyrimidin-7(4H)-ones as novel Kv7/KCNQ potassium channel activators

Eur J Med Chem. 2011 Mar;46(3):934-43. doi: 10.1016/j.ejmech.2011.01.010. Epub 2011 Jan 22.


Voltage-gated Kv7/KCNQ/M-potassium channels play a pivotal role in controlling neuronal excitability. Genetic reduction of KCNQ channel activity as a result of mutations causes various human diseases such as epilepsy and arrhythmia. Therefore, discovery of small molecules that activate KCNQ channels is an important strategy for clinical intervention of membrane excitability related disorders. In this study, a series of pyrazolo[1,5-a]pyrimidin-7(4H)-ones (PPOs) have been found to be novel activators (openers) of KCNQ2/3 potassium channels through high-throughput screening by using atomic absorption rubidium efflux assay. Based on structure-activity relationship (SAR), the substituted PPOs have been optimized. The 5-(2,6-dichloro-5-fluoropyridin-3-yl)-3-phenyl-2-(trifluoromethyl) pyrazolo[1,5-a]pyrimidin-7(4H)-one (17) was identified as a novel, potent, and selective KCNQ2/3 potassium channel opener by patch-clamp recording assay.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrhythmias, Cardiac / drug therapy
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Drug Design
  • Epilepsy / drug therapy
  • Humans
  • KCNQ Potassium Channels / metabolism*
  • Patch-Clamp Techniques
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry*
  • Pyrazoles / pharmacology*
  • Pyrimidines / chemical synthesis
  • Pyrimidines / chemistry*
  • Pyrimidines / pharmacology*
  • Rubidium / metabolism
  • Structure-Activity Relationship


  • KCNQ Potassium Channels
  • Pyrazoles
  • Pyrimidines
  • Rubidium