4596-77-4Relevant articles and documents
Reaction of (E)-β-Enamino Amides with Dimethyl Acetylenecarboxylate (DMAD): Formation of Benzene Derivatives, Enamino Esters, and 2-Pyridones
Nuvole, Antonio,Paglietti, Giuseppe
, p. 1007 - 1011 (2007/10/02)
An investigation of the additions of (E)-enamino amides (1a-d) with DMAD has shown that they are influenced by the stereochemistry of the intermediates and the amine component of the enamine system.In dry acetonitrile (E)- benzyl(methyl)amino- (1b), (E)-pyrrolidin-1-ylamino-(1c), and (E)-piperidin-1-ylamino-(1d) acrylamides, following a known mechanism, yielded tetramethyl benzene-1,2,3,4-tetracarboxylate (5), the (E)-aminobutenedioates (6a-d), and the 3,4-bismethoxycarbonylpyridin-2(1H)-one (8).Dimethylamino-(1a) and morpholin-1-ylamino-(1e)-acrylamides, owing to the different nucleophilicity of the β-carbon, formed a zwitterion (11) which eliminated propiolamide to give only the (E)-aminobutenedioates (6a,e).