| Abstract: |
This thesis is prefaced by a survey on the biological activities of 3,5- disubstituted-l ,2,4-triazoles, as well as the hypoglycemic activity of 1,2,4-triazole derivatives .The present investigation is concerned with the synthesis of 5-animo and 3(5)-chloro-1,2,4-triazole-5(3)-carboxylic acid derivatives.The key intermediate methyl ester of 5-amino-1,2,4-triazole-3-carboxylic acid II was prepared by the reaction of aminoguanidine bicarbonate and oxalic acid dihydrate, the resulting oxalyl aminoguanidine was cyclized in alkaline medium to give 5-amino-1,2,4-triazole-3-carboxylic acid I which was esterified by methyl alcohol saturated with hydrochloric acid to give II. Reacting II with the appropriate amine yielded the corresponding carboxylic acid derivatives III a-g. Semicarbazide, thiosemicarbazide and iminosemicarbazide IIIh-j were prepared from hydrazide IIIg by reaction with urea, ammonium thiocyanate and guanidine hydrochloride.3(5)-Chloro analogues were prepared by diazotization of the amino ester II, and the obtained diazonium salt in presence of hydrochloric acid yielded methyl . 3(5)-chlqro-l,2,4-triazole-5(3)-carboxylate IV. Reaction of IV with ammonia, primary amines, hydroxylamine, hydrazine hydrate, semicarbazide hydrochloride and aminoguanidine bicarbonate gave the planned derivatives Va-b-j thiosemicarbazide Vi was prepared by the reaction of the hydrazide Vg with ammonium thiocyanate. 3(5)- chloro-5- carboxamides Va-e were prepared from the corresponding 5-amino derivatives IIIa-e via diazotization and nucleophilic replacement by chloride ions.
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