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Neue Synthesen von 1,3‐Oxazinen, Thiazolen und 1,2‐Dithiolen
Author(s) -
Capuano Lilly,
Bolz Gerda,
Burger Robert,
Burkhardt Volker,
Huch Volker
Publication year - 1990
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199019900143
Subject(s) - chemistry , dehydrogenation , nucleophile , diazo , medicinal chemistry , stereochemistry , organic chemistry , catalysis
New Syntheses of 1,3‐Oxazines, Thiazoles, and 1,2‐Dithioles The 2‐diazo‐1,3‐diketones 1 react with thioamides 4 via the acyl ketenes 3 , resulting from Wolff rearrangement, to give the 1,3‐oxazine‐4‐ones 10; however, by increasing the electro‐philicity of the diazo compounds or the nucleophilicity of the thioamides, the 5‐acylthiazoles 9 are obtained. These are derived from the diketocarbene intermediates 2 . The structure of 9g was confirmed by X‐ray diffraction analysis. — The best preparative method for 1,3‐oxazinones consists in the dehydratation of the 2, N ‐diacylacetamides 8 , which are readily available from the reaction of diazodiketones with carboxamides. — The thionation of 8 or 10 with P 4 S 10 proceeds with spontaneous dehydrogenation, affording high yields of 3‐(thiobenzoylimido)‐1,2‐dithioles 15 . The structure of 15a was established by X‐ray diffraction analysis.