This invention relates to pyridazine derivatives, compositions comprising therapeutically effective amounts of those pyridazine derivatives and methods of using those derivatives or compositions in treating central nervous system (CNS) disorders with cognitive impairment that are responsive to agonists of ±5 subunit containing GABA A receptor, e.g. , age-related cognitive impairment, Mild Cognitive Impairment (MCI), dementia, Alzheimer's Disease(AD), prodromal AD, post traumatic stress disorder (PTSD), schizophrenia and cancer-therapy-related cognitive impairment.