Synthesis and SAR Study of the Novel Thiadiazole-Imidazole Derivatives as a New Anticancer Agents.

In the present study, a novel series of 2-(2-(3-aryl-5-substituted-1,3,4-thiadiazol-2(3H)-ylidene)hydrazinyl)-4,4-diphenyl-1H-imidazol-5(4H)-one derivatives were designed and prepared via the reaction of the most versatile, hitherto unreported 2-(5-oxo-4,4-diphenyl-4,5-dihydro-1H-imidazol-2-yl)-N-phenylhydrazinecarbothioamide with the appropriate hydrazonoyl halides. In addition, some thiazole derivatives were prepared. The structures of the newly synthesized compounds were established based on spectroscopic evidences and their alternative syntheses.

Efficient routes to pyrazolo[3,4-e][1,2,4]triazines and a new ring system: [1,2,4]triazino[5,6-d][1,2,3]triazines.

Arylhydrazonomalononitriles 1a,b react with phenylhydrazine to yield amidrazones 2a,b that cyclize to give 2-aryl-5-phenylhydrazono-2,5-dihydro-[1,2,4]-triazine-6-carbonitriles 5a,b upon reaction with dimethylformamide dimethylacetal (DMFDMA). Refluxing 5a,b in glacial acetic acid resulted in the formation of the pyrazolo-1,2,4-triazines 6a,b. Compounds 6a,b were also formed upon treatment of 3-amino-4-phenylhydrazono-1-phenyl-2-pyrazolin-5-ones 7a,b with DMFDMA.