Synthesis of some substituted multinuclear 1,3,4-oxadiazoles and 1,3,4-thiadiazoles

Abstract EN

The synthesis of multinuclear heterocyclic system containing substituted 1,3,4-oxadiazole and 1,3,4-thiadiazole ring was achieved from suitable esters which were converted to the corresponding acid hydrazides by their reaction with hydrazine hydrate in ethanol.

The treatment of acid hydrazide with phosgene or with carbon disulfide gave substituted oxadiazole-2-one or 2-thiol respectively.

5-Phenyl-1,3,4-oxadiazole-2-thiol was treated with 2-chloro-5-phenyl-1,3,4-thiadiazole in ethanolic potassium hydroxide solution to give (5-phenyl-1,3,4-oxadiazol-2-yl) (5-phenyl-1,3,4-thiadiazol-2-yl) sulfide, whereas the reaction of 1-[5-(4-aminophenyl)-1,3,4-oxadiazol-2-yl] hydrazine and 5-(4-aminophenyl)-2-amino-1,3,4-thiadiazole with 5-phenyl-2-chloro-1,3,4-thiadiazole gave 1-[5-{4-N-(5-phenyl-1,3,4-thiadiazol-2-yl) aminophenyl}-1,3,4-oxadiazole-2-yl] 2-[5- phenyl-1,3,4-thiadiazol-2-yl] hydrazine and [5-{4-N-(5-phenyl-1,3,4-thiadiazole-2-yl)aminophenyl}-1,3,4-thiadiazol-2-yl] [5-phenyl-1,3,4-thiadiazol-2-yl] amine respectively.

The structure of synthesized compounds was established by physical and spectral means.