this invention encompasses compounds of formula i : ## str1 ## or the pharmaceutically acceptable non - toxic salts thereof wherein : ## str2 ## represents : ## str3 ## where n is 0 , 1 , or 2 ; r 1 and r 2 are hydrogen or straight or branched chain alkyl groups ; y represents various organic and inorganic substituents ; w represents an aromatic group substituted with various organic and inorganic substituents ; a is ch or n ; b is a substituted or unsubstituted carbon or n ; and e is hydrogen or straight or branched alkyl groups . these compounds are highly selective agonists , antagonists or inverse agonists for gabaa brain receptors or prodrugs thereof and are useful in the diagnosis and treatment of anxiety , sleep , and seizure disorders , overdose with benzodiazepine type drugs , and enhancement of alertness .