Heterocyclic-fused pyrazolo-[3,4-d]pyridin-3-ones as benzodiazepine receptor modulators

Claim 1

A compound of the formula ##STR11## or ##STR12## wherein A together with the two carbon atoms to which it is attached represents a fused heterocyclic ring selected from (a) thieno, furo, and N-unsubstituted or N-lower alkyl substituted pyrrolo, wherein the carbon atoms in any of said rings are unsubstituted or one of them is substituted by lower alkyl, carbo-(lower)-alkoxy, halogen or trifluoromethyl; (b) N-unsubstituted or lower alkyl substituted-imidazo, wherein the carbon atom in said ring is unsubstituted or substituted by lower alkyl, lower alkoxy, halogen or trifluoromethyl; (c) thiazolo, oxazolo, isoxazolo, and pyridazino, wherein the carbon atoms forming any of said rings are unsubstituted or one or two are substituted by lower alkyl, lower alkoxy or halogen; (d) pyrimido and pyrazino wherein the carbon atoms in any of said rings are unsubstituted or one is substituted by lower alkyl or lower alkoxy; R 1 represents phenyl, or phenyl mono- or disubstituted by lower alkyl, lower alkoxy, halogen or trifluoromethyl; or R 1 represents an aromatic heterocyclic radical selected from pyridyl, quinolyl, isoquinolyl, pyrimidyl and thiazolyl, or any said heterocyclic radical mono- or di-substituted by lower alkyl, lower alkoxy or halogen; R 2 , R 3 and R 3 ' independently represent hydrogen or lower alkyl; or a pharmaceutically acceptable salt thereof.