Efficient synthesis of 1,3,4-oxadiazoles conjugated to thiophene or furan rings via an ethenyl linker

Article abstract of DOI:10.1055/s-0033-1338454

A novel and efficient synthesis of 5-substituted 2-[2-(2-furyl)ethenyl]-1, 3,4-oxadiazoles and 2-[2-(2-thienyl)ethenyl]-1,3,4-oxadiazoles by cyclocondensation of the appropriate 3-(2-furyl)- and 3-(2-thienyl) acrylohydrazides with triethyl orthoesters in the presence of glacial acetic acid is reported. The formation of symmetrically substituted 2,5-bis[2-(2-furyl)ethenyl]-1,3,4-oxadiazole and 2,5-bis[2-(2-thienyl)ethenyl]- 1,3,4-oxadiazole from the corresponding N,N′-diacylhydrazines under the influence of phosphorus oxychloride is also described. Georg Thieme Verlag Stuttgart. New York.