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

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 H-1- and C-13-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.

Automated summary

This study details the reaction of dimethyl acetylenedicarboxylate with aniline derivatives, showing the diasteromeric enamines obtained were characterized using H-1 and C-13 NMR spectra and computational methods. The heterocyclization reactions of the isolated diasteromeric enamines resulted in different products depending on reaction conditions and substrate characteristics, leading to the discovery of new routes for synthesizing specific derivatives.