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Azepinones, tautomerism

Dibenzazepin-2-one, 5-aminomethyl-transannular nucleophilic attack, 7, 25 Dibenzazepin-2-ones tautomerism, 7, 503 Dibenz[6,dJazepinones phenanthridinones from, 2, 507 synthesis, 7, 530 Dibenz[6,d]azepinones, hydrosynthesis, 7, 536 Dibenz[6,eJazepinones synthesis, 7, 529, 530 5H-Dibenz[c,eJazepin-7-ones synthesis, 7, 529... [Pg.599]

A possible mechanism for the observed transformation includes the sequence outlined in Scheme 2.327 (i) propargyl (A) - allene (B) tautomerization, (ii) 8jt-cyclization (C), (iii) N-0 cleavage (diradical D), (iv) diradical recombination (cyclopropanone derivative E), and (v) one or two step cyclizations of the azadienyl cyclopropanone into azepinone F. The occurrence of cyclopropanones (type E), as intermediates, is supported by the formation, in some cases, of isoindoles (type I) (789) as minor products (Scheme 2.327) (139, 850, 851). [Pg.393]

When 4-azidophenols such as 89 (X = Y = Cl) were photolyzed in Nj matrices, azepin-4-ones (91) were the major products, presumably arising by tautomerization of the corresponding hydroxy-substituted cyclic ketenimines (90). In some cases, the ketenimine was observed directly in the IR spectra. Tautomerization to give the azepinones was favored in more concentrated matrices, suggesting that this process involved intermolecular proton transfer between pairs or aggregates of ketenimine molecules. Matrix photolysis of 4-azidophenols held out the promise of a synthetic route to the elusive azepin-4-ones under exceptionally mild conditions and was tried on preparative scales up to 50 mg or more in a specially constructed matrix-isolation ceU. Unfortunately, the azepinones did not survive warm-up at the end of the experiments, and only polymeric products were ultimately obtained. [Pg.278]


See other pages where Azepinones, tautomerism is mentioned: [Pg.524]    [Pg.524]    [Pg.524]    [Pg.524]    [Pg.319]   


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