SYNTHESIS OF SOME THIAZOLE DERIVATIVES, 1,3,4-THIADIAZOLE DERIVATIVES, AND 4H-1,2,4-TRIAZOLE DERIVATIVES OF PYRAZOLO[3,4-B]QUINOLINE

Three novel series of pyrazolo[3,4-b]quinolines were perpared, namely: 1-(3-substituted-4-phenylthiazolin-2-ylidene)hydrazinocarbonylmethyl-H-1-pyrazolo[3,4-b]quinolines 3a-d; 1-(5-substituted amino-1,3,4-thiadiazol-2-yl)methyl-H-1-pyrazolo[3,4-b]quinolines 4b-d, and 1-(4-substituted-4H-5-thioxo-1,2,4-triazole-3-yl)methyl-1H-pyrazolo[3,4-b]quinolines 5a-d. These compounds were prepared by cyclization of the new key intermediates 1-(substituted thiocarbamoylhydrazinocarbonyl)methyl-H-1-pyrazolo[3,4-b]quinolines 2a-d. The alkylthio, aralkylthio 6a-f as well as the Mannich bases 8a-f derived from compounds 5a-d were also prepared. The structures of the new compounds were elucidated by elemental analyses, IR, H-1-NMR-, and mass spectra. The antimicrobial as well as inotropic and chronotropic activities were studied.