Synthesis and anticonvulsant activity of 7-alkoxyl-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinolines

A series of 7-alkoxyl-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinoline derivatives was synthesized using 6-hydroxy-3,4-dihydro-1H-quinolin-2-one as a starting material. Their anticonvulsant activities were evaluated by the maximal electroshock test (MES test) and the subcutaneous (sc) pentylenetetrazol test (scMet test), and their neurotoxicity was evaluated by the rotarod neurotoxicity test (Tox). MES and scMet tests show that 7-(4-fluorobenzyloxy)-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinoline 4l was found to be the most potent with ED50 value of 11.8 and 6.7 mg kg−1 and protective index (PI = TD50/ED50) value of 4.6 and 8.1, respectively.