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

► A series of novel pyrazolo [1,5-a] pyrimidin-7(4H)-ones (PPOs) were synthesized. ► A few lead compounds as M channel openers were identified. ► Structure-activity relationships of PPOs as M channel openers were established. ► Derivatives of PPOs were identified as the novel Kv7/KCNQ channel openers.