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Nitrogen bridgehead compounds, part 68 . Studies on quinolizine derivatives. Part 2 . Synthesis of 1,3‐disubstituted‐4 H ‐quinolizine derivatives
Author(s) -
Schwartz Angéla,
Pál Zoltán,
Szabó László,
Simon Kálmán,
Hermecz István,
Mészáros Zoltán
Publication year - 1987
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570240320
Subject(s) - chemistry , tautomer , stereochemistry , nitrogen , base (topology) , medicinal chemistry , organic chemistry , mathematical analysis , mathematics
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 1 H nmr spectra, that of 3B=C by X‐ray analysis as well.