Reaction of Ethyl Acetoacetate with p-Toluenesulfonic Acid : Formation of Ethyl Isodehydroacetate and/or Ethyl p-Toluenesulfonate

Abstract

Treatment of ethyl acetoacetate with anhydrous p-toluenesulfonic acid at room temperature led to ethyl isodehydroacetate (1) in high yield by acid-catalyzed condensation. On the other hand, in refluxing toluene, the unexpected ethyl ester of p-toluene-sulfonic acid (2) was formed in moderate yield. This constitutes a new direct esterification of arenesulfonic acids.