Study of the Hydroamination Reaction of Methyl Acetylenedicarboxylate with Aromatic Amines and its Heterocyclization Products

Abstract

Here we describe the reaction of dimethyl acetylenedicarboxylate with aniline, N-ethylaniline or diphenylamine. The diasteromeric enamines obtained in each case are inequivocally characterized by 1H- and 13C-NMR spectra and computational methods. The heterocyclization reaction of each isolated diasteromeric enamines, leads to different products depending on the reaction conditions and the stereoelectronic characteristics of the substrate. Thus, we were able to obtain 1-phenyl-2-methoxycarbonyl-4-quinolinone, and to find a new route for obtaining 1-phenyl-3-oxo-1,3-dihydro-2-indoliliden-acetic acid derivatives.