Design of benzothiazole-1,3,4-thiadiazole conjugates: synthesis and anticonvulsant evaluation.

Various 2-[(6-substituted-1,3-benzothiazol-2-yl)amino]-N-[5-substituted-phenyl-1,3,4-thiadiazol-2-yl]acetamides were synthesized with a prospective exploration of "lead hopping", using pharmacophoric elements for in vivo anticonvulsant activity. This yielded three potent candidates (5i, 5t, and 5u) in the preliminary screening employing the maximal electroshock seizure (MES) and the subcutaneous pentylenetetrazole (scPTZ) test, showing minimal neurotoxicity. Their quantitative study indicated an increase of nearly 2-10 times for the MES test and 7- to 67-fold for the scPTZ test in the protective index, the keystone in drug discovery for anticonvulsant activity.