The present invention encompasses structures of the Formula or the pharmaceutically acceptable non-toxic salts thereof wherein: X is hydrogen, halogen, (un)substituted alkyl, (un)substituted alkoxy or amino; and Y is (un)substituted alkyl, aryl, or heteroaryl, which compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. These compounds are useful in the diagnosis and treatment of anxiety, Down Syndrome, sleep, cognitive and seizure disorders, and overdose with benzodiazepine drugs and for enhancement of alertness.