Synthesis Of 1,2,4-triazoles And 1,3,4-oxadiazoles Containing Benzo[b] Furan

Heterocyclic compounds, especially triazolo and thiadiazole have a wide range of biological and pharmacological activity. Heterocyclic compounds and their derivatives as intermediates of pesticides, pharmaceuticals, dyes and other fine chemical products have already been widely applied. Scientists around the world very concerned about the synthesis of these compounds.Substituted l,3,4-oxadiazoles have been of great interest to the medicinal chemists for many years because of their antimicrobial, antimitotic, antiinflammatory, psychotropic, antiaflatoxigenic, and anticonvulsant activities. Benzo[b]furan derivatives are of interest because of their frequent occurrence in nature and their wide range of biological effects.Seriesâ… : Synthesis of 2-[4-amino-5-(2'-benzofuranyl)-1,2,4-triazol-3-th- iol]-N-phenylacetamide in PEG-400. The key intermediate 4-amino-3-[2'-benzo(b) ruryl]-5-mercapto-1,2,4-triazole was prepared by the reaction of 2-benzofuranearb- oxylic acid hydrazide with CS₂ and NH₂NH₂. The reaction of 4-amino- 3-[2'-benzo(b)furyl]-5-mercapto-1,2,4-triazole with 2-chloro-N-phenylacetamide in PEG-400 affords 12 2-[4-amino-5-(2'-benzofuranyl)-1,2,4-triazol-3-thiol]-N-pheny- lacetamides. Considerable increase in reaction rate has been observed with improved.Seriesâ…¡: Synthesis of 2-[5-(2'-benzofuranyl)-1,3,4-oxadiazole-2-thiol]-N-ary- lacetamides under microwave irradiation. The key intermediate 5-[2'-benzo(b)ru- ryl]-2-mercapto-1,3,4-oxadiazole was prepared by one-step reaction of 2-benzofur- anearboxylic acid hydrazide with CS₂. The reactions of 5-[2'-benzo(b)furyl]-2-mercapto-1,3,4-oxadiazole with 2-chloro-N-phenylacetamides afford 12 new 2-[5-(2'-benzofuranyl)-1,3,4-oxadiazole-2-thiol]-N-arylacetamides.The structures of all compounds were confirmed by IR, ¹H NMR, ¹³C NMR, Elemental analysis and MS.