ISOXAZOLO-PYRIDAZINE DERIVATIVES

摘要

The invention relates to compounds of formula (I) wherein X is O or NH; R1 is phenyl, pyridinyl, or pyrimidinyl each optionally substituted with one, two or three halo, R2 is C1-4alkyl, H or C1-4haloalkyl; R3, R4, and R5 each are independently H, optionally substituted Ci-7alkyl, optionally substituted C?.7alkoxy, CN, halo, NO2, -C(O)-Ra -NRbRc, optionally substituted 3- to 7-membered heterocyclyl, optionally substituted 5- or 6-membered heteroaryl, -C(0)-NRdRe, or R3 together with the neighboring pyridazine-nitrogen form a 5-membered optionally substituted annelated aromatic ring with two additional ring nitrogen atoms, or to a pharmaceutically acceptable salt thereof, having affinity and selectivity for the GABA A a5 receptor binding site, their manufacture, pharmaceutical compositions containing them and their use as medicaments. The active compounds of the present invention are useful as cognitive enhancers or for the treatment of cognitive disorders like Alzheimer's disease.