Collect. Czech. Chem. Commun. 1992, 57, 1072-1080

1-Ethoxycarbonylquinolizinium Salts Condensation of β-Ketoenol Ethers with 2-Pyridylacetates

Jerzy Szychowski, Andrzej Leniewski, Jerzy T. Wróbel and Tomasz Glinka

Department of Chemistry, Warsaw University, 02093 Warsaw, Poland


A general route to some 1-ethoxycarbonylquinolizinium bromides has been worked out. The method allows to conduct the condensation between β-ketoenol ethers and substituted 2-pyridylacetates in homogenous conditions in the presence of trifluoroacetic acid in an aprotic solvent. The substitution at C-6 in 2-pyridylacetates completely changes the reaction course affording 3,6-disubstituted 2-pyrones.