PREPARATION OF ENAMINES FROM THE CONDENSATION OF GLYCINE ESTERS WITH NITRO-HETEROCYCLIC ALDEHYDES

In order to prepare the imine derived from condensation of glycine eth yl ester and 5-nitrothiophene-2-carboxaldehyde, another compound was o btained instead. This product was the enamine, ethyl 2-amino-3-(5-nitr o-2-thienyl)-2-propenoate, resulting from the condensation between the methylene of the glycine derivative and the heterocyclic carbonyl gro up. The reactivity of related amines and heterocyclic aldehydes was st udied in order to get more insight about tile mechanism of enamine for mation. It was found that the nitro-heterocyclic group and the easy of enolization of the aminoacidic ester played an important role.