| abstract |
The present invention provides a compound of formula (I) having affinity and selectivity for the GABA Aα5 receptor binding site wherein X is O or NH; R 1 is phenyl, pyridinyl, or pyrimidinyl (each optionally 1 R 2 is C 1-4 alkyl, H or C 1-4 haloalkyl; R 3 , R 4 , and R 5 are each independently H, optionally substituted C 1-7 alkyl, optionally substituted C 1-7 alkoxy, CN, halo, NO 2 , —C (O) —R a , —NR b R c , Optionally substituted 3-7 membered heterocyclyl, optionally substituted 5-6 membered heteroaryl, —C (O) —NR d R e , or R 3 represents an adjacent pyridazine-nitrogen and 2 together Form an optionally substituted 5-membered cyclized aromatic ring having an additional ring nitrogen atom] or a pharmaceutically acceptable salt thereof, their preparation, a pharmaceutical composition containing them, and Relates to their use as medicaments. The active compounds of the invention are useful as cognitive enhancers or for the treatment of cognitive disorders such as Alzheimer's disease. |