Base catalyzed reaction of ethyl thioglycolate with β-aryl-β-(methylthio) acroleins: a general method for the synthesis of 2-carbethoxy-5-substituted/4,5-annulated thiophenes in high overall yields
were shown to be stable unlike their counterpart the chloroacroleins and their efficacy as 1,3-dielectrophilic properties have now been examined successfully in this work. They are shown to react with ethyl thioglycolate in the presence of anhydrous potassium carbonate in boiling ethanol to yield the corresponding 5-substituted/4,5-annulated-2-carbethoxy thiophenes in 70–80% overall high yields.