6-, 7- AND 8-(5-ARY L-1-PHENYL-2-PYRAZOLIN-3-LY)IMIDAZO- AND PYRIMIDO[2,1-b]BENZOTHIAZOLES AS NOVEL ANTICONVULSANT AGENTS

Some new derivatives of 2-amino-5- and 6-(5-aryl-1-phenyl-2-pyrazolin-3-yl)benzothiazole were synthesized from the corresponding aminophenyl compounds by reaction with KSCN/Br₂ to build up the benzothiazole ring. The aminophenyl derivatives of pyrazoline were prepared by cyclization with phenylhydrazine of the appropriate 1,3-diphenyl-2-propen-1-one derivatives obtained from arninoacetophenone and differently substituted aldehydes. However, the newly synthesized 2-aminobenzothiazole derivatives of pyrazoline were subjected to cyclization with ethyl brornopyruvate to afford the formation of 6- and 7-(5-aryl-1 -phenyl-2-pyrazolin-3 -yl)-2-ethoxycarbonylimidazo[2,1-b]benzothiazole derivatives. Furthermore, dimethyl acetylenedicarboxylate (DMAD) was used as another cyclizing agent for 2-aminobenzothiazole derivatives to obtain 7- and 8-(5-aryl-1-phenyl-2-pyrazolin-3-y1)-4-methoxycarbonyl-2-oxo-2H-pyrimido[2,1-b]benzothiazole derivatives. The newly prepared compounds were screened for their anticonwlsant activities. However, some of the tested compounds manifested good anticonvulsant potencies.