Rapid microwave-assisted solution phase synthesis of 6, 8-disubstituted- 2-phenyl-3-(substituted-benzothiazole-2-yl) – 4-[3H]-quinazolinone as novel anticonvulsants

A fast and highly efficient microwave accelerated solution phase procedure for the synthesis of a series of 2-phenyl-3-(substituted-benzothiazole-2-yl) - 4[3H]-quinazolinone is developed and title compound was characterized by elemental analyses and spectral (IR, 1H NMR and EI-MS) data. The anticonvulsant activity of all the title compounds (3a-m &4a-m) were evaluated against Maximum Electroshock (MES) induced seizures and further more the compounds were evaluated against subcutaneous pentylenetetrazole (PTZ) induced seizures model in mice. The neurotoxicity was assessed using Rotorod procedure. All the test compounds were administered intraperitoneally at a various dose levels ranging from 7-200 mg/Kg body wt and the median toxic dose (TD50) and protection index (PI) values were determined and reported. In general compounds 3a-m were found to be more potent compared to compounds 4a-m. Among the compound tested , the compound 3e in 2-phenyl-3-(substituted-benzothiazole-2-yl) – 4-[3H]-quinazolinones series and compound 4l in 6,8, dibromo 2-phenyl-3-(substituted-benzothiazole-2-yl) – 4-[3H]-quinazolinones series were found to be the most potent.