Compounds according to Formula (I) or a pharmaceutically acceptable salt thereof are GABA-A Alpha 5 ligands useful for enhancing cognition:where A is C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C3-6cycloalkyl, arylC1-6alkyl, or aryl wherein the aryl group is optionally substituted by halogen, C1-6alkyl, CF3, CN, NO2 or NH2, NR1R10, S(O)pR1, heteroarylC1-6alkyl or heteroaryl where heteroaryl is a 5- or 6-membered heteroaromatic ring as defined for B; and B is phenyl or a 5-membered ring having one or two unsaturations containing 1, 2, 3, or 4 heteroatoms chosen from O, N and S provided that not more than one heteroatom is other than N, a 6-membered heteroaromatic ring containing 1, 2, 3 or 4 nitrogen atoms, each of which rings is optionally substituted by one or more substituents.
Tetrahydroindolone derivatives as gabaaalpha5 ligands for enhancing cognition