Reactions with Heterocyclic β-Enaminoesters: A Novel Synthesis of 2-Amino-3-ethoxycarbonyl-(4H)-pyrans

Article abstract of DOI:10.1007/BF00814337

The reaction of ethyl cyanoacetate with α-cyanochalcone (1) leads to the formation of β-enaminoesters (3) via Michael addition.Compound 3 reacts with phenylmagnesium bromide to give the β-enaminoketone 5.Acetylation of 3 gives the acetyl product 4.Each of compounds 1 and 3 reacts with malononitrile to give β-enaminonitrile 6.Phenylhydrazine reacts with 3 to give the hydrazone 7.Similarly 3-phenyl-5-aminopyrazole reacts with 3 to give the Schiff base 8. - Keywords: Enaminopyrans; Michael addition; Pyrans, cleavage of