الملخص

Abstract The conversion of some acid chlorides to substituted 1,3,4-oxadiazole, 1,3,4-thiadiazoles and 1,2,4-triazoles is reported. Benzoyl chloride and 4- nitrobenzoyl chloride were treated with hydrazine hydrate in ethanol to give acid hydrazides (1,2), The acid hydrazides were converted to 1- substituted thiosemicarbazides (3,4) by this reaction with ammonium thiocyanate in ethanol. The later thiosemicarbazides were cyclized to substituted thiadiazoles (5,6) and triazoles (7,8) by their reaction with concentrated sulphuric acid and sodium hydroxide solution respectively. The hydrazones (9-12) were synthesised from acid hydrazides (1,2) by their reaction with substituted benzaldehyde in dioxane. The cyclization of hydrazones (9-12) with acetic anhydride gave substituted 1,3,4- oxadiazole (13-16). The structures of synthesised compounds were confirmed by IR, UV spectral data and physical means.