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Abstract The present dissertation describes the utility of hydrazonoyl halides in the synthesis of heterocyclic compounds by treatment each of N-(4-nitrophenyl)isobutyrohydrazonoyl bromide 1 and N-phenyl-substituted benzenecarbohydrazonoyl chlorides 2Aa-d with malononitrile in sodium ethoxide solution afforded the corresponding 5-aminopyrazole-3-carbonitrile 6 and 15-18, respectively, which were converted to ethyl-N-(4-cyano-1-(aryl)-1H-pyrazol-5-yl)formimidate derivatives 7 and 19-22 upon refluxing with TEOF in acetic anhydride. Stirring of the latter product with hydrazine hydrate afforded 4-imino-1-(aryl)-1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-amine derivatives 8 and 23-26, which were converted to hydrazino derivatives 9 and 27-30 by refluxing with hydrazine hydrate. Hydrazino as well as imino amino derivatives undergo condensation and cyclization reactions to give pyrazolo[3,4-d]pyrimidine, and pyrazolo[4,3- e] [1,2,4]triazolo[3,4-c]pyrimidine derivatives, respectively. Imino amino derivatives 24-26 undergo cycloaddition reaction with Ü-ketohydrazonoyl halides to give 3-methyl-8-phenyl-4,8-dihydropyrazolo-[3’,4’:4,5]-pyrimido[1,6-b][1,2,4]triazine 54-56. Also, reaction of 6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one 57 with hydrazonoyl chlorides 2-4 in refluxing chloroform in the presence of triethylamine yielded triazolotriazine derivatives 64. The hydrazino derivative 68 undergoes condensation reactions with aldehydes, pyruvic acid, ethyl pyruvate and ketones to give the corresponding hydrazone derivatives 69,70 |