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Pyridinethiones. VIII. The aldol and wittig condensations of 3‐formyl‐2(1 H )‐pyridones, ‐thiones and ‐selones. Preparation of new cyanopyridones
Author(s) -
Michael Maged Aziz,
Becher Jan,
Winckelmann Ib
Publication year - 1983
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.5570200643
Subject(s) - chemistry , wittig reaction , acetophenone , aldol reaction , aldol condensation , ammonium acetate , condensation , benzaldehyde , organic chemistry , medicinal chemistry , catalysis , high performance liquid chromatography , physics , thermodynamics
Condensations of 1‐substituted‐3‐formyl‐2(1 H )‐pyridones, ‐thiones and ‐selones with methyl ketones such as acetophenone give the corresponding chalcones in high yields. Geometry at the vinyl hydrogens is E. These chalcones can be cyclized with ethyl cyanoacetate in the presence of ammonium acetate to form new 3‐cyano‐2(1 H )‐pyridones. An effective “one‐pot” preparation is worked out and an intermediate from the cyclization reaction is isolated. Via the Wittig reaction it is possible to prepare condensation products from 1‐substituted‐3‐formyl‐2(1 H )‐pyridinethiones and ‐selones with mainly Z geometry at the vinyl hydrogens.