Azabutadiene Derivatives in the Synthesis of Five-Membered Heterocycles. Unequivocal Synthesis of 1H-Pyrrole-2-carboxylates

Article abstract of DOI:10.1021/jo00348a017

1,3-Diimines 1 react with glycine ethyl ester hydrochloride 2 as well as ethyl chloroacetate 9 in pyridine, giving rise to 1H-pyrrole-2-carboxylates 8 in both cases.The formation of heterocycles 8 can be explained in terms of an electrocyclic closure of t