Quinolizine compounds 1 and 2 or their monocyclic tautomers 3 and 4 have been synthesized using 2‐pyri‐dineacetic acid derivatives 6a, b, A, B and ethoxymethylenemalonic acid derivatives 7a, b, c in base catalyzed or thermic reaction. In the 6‐unsubstituted series, both the 4‐oxo and 4‐imino derivatives could have been obtained, in the 6‐substituted series, however the 4‐oxo ones only, whereas instead of the 4‐imino derivatives, their monocyclic tautomers 3, 4 have been isolated. In the 6‐unsubstituted series, the primarily formed 4‐imino compounds have been rearranged into 4‐oxo ones under stronger conditions. The structure of the isolated compounds have been proved by ultraviolet, infrared and 1H nmr spectra, that of 3B=C by X‐ray analysis as well.
ASJC Scopus subject areas
- Organic Chemistry