Morpholines-(III): Some Further Aspects of the Cyclodehydrohalogenation of ω -[N-(aryl)-N-(halogenoacyl)]-aminoacetophenones
Open Access
- 1 February 1971
- journal article
- Published by Walter de Gruyter GmbH in Zeitschrift für Naturforschung B
- Vol. 26 (2) , 95-98
- https://doi.org/10.1515/znb-1971-0208
Abstract
The formation of a 2-oxo-azetidine from N-phenyl-N-chloroacetyl-4-fluoro-phenacylamine, and 3-oxo-morpholines from corresponding 4-bromo-derivatives 2 indicates the possibility of the existence of dπ-acceptor resonance between the aromatic ring and the bromo-substituent. H-NMR studies of some morpholines reported earlier 3 indicate a planar heterocyclic structure with a rapidly inverting N₋aryl substituent. Where the rotation of the N-aryl group is strongly hindered 16, the C2 methylene protons show a geminai coupling of -14.5 Hz4. The 2-oxo-azetidine (4) shows an ABX coupling pattern for its ring protons. Preliminary work attempting to extend the synthesis of morpholines to azepines has resulted instead in the formation of a pyrrolidone.Keywords
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