الملخص

In this paper the synthesis of methyl-6- methyl-2-oxo-4-substituted phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (1-3) were synthesised from substituted benzaldehyde, urea and methyl acetoacetate, substituted pyrimidine (1-3) were treated with hydrazine hydrate in butanol to give acid hydrazide (4-6), which were converted to hydrazones (7-12) by their reaction with substituted benzaldehyde. Cyclizatian of hydrazones (7-12) with lead dioxide in glacial acetic acid gave substituted 1,3,4- oxadiazole (13-18). Hydrazide (4-6) were treated with ammonium thiocyanate in ethanol and hydrochloric acid to give substituted thiosemicarbazides(19-21). Reaction of thiosemicarbazide (19-21) with 4% sodium hydroxide or with concentrated sulfuric acid gave substituted 1,2,4- (4H) - triazole (22-24) and 1,3,4- thiadiazole (25-27) respectively. The structure of the synthesized compounds, were confirmed by IR, UV and physical methods.