Pharmacological evaluation of 2-substituted (1,3,4) thiadiazolo quinazolines

A series of 2-Substituted (1,3,4) thiadiazolo quinazolines were synthesized by the cyclocondensation of 3-amino-2-mercapto quinazolin-4(3H)-ones with various one-carbon donors and screened for their CNS activities (analgesic, anti-inflammatory, sedative-hypnotic and anticonvulsant). Compound III showed good CNS depressant activity, and it is comparable with the reference standard diazepam. While all the test compounds offered significant protection against strychnine-induced and hypoxic induced convulsion, compound III exhibited equivalent activity with the standard diazepam at the dose tested, and it was found to be significant when compared to control.