Synthesis of some Substituted Multinuclear 1,3,4- Oxadiazoles and 1,3,4-Thiadiazoles

Abstract

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.