19479-87-9Relevant articles and documents
The reaction of hydroxylamine with aspirin
Medeiros, Michelle,Souza, Bruno S.,Orth, Elisa S.,Brandao, Tiago A. S.,Rocha, Willian,Kirby, Anthony J.,Nome, Faruk
scheme or table, p. 461 - 476 (2011/10/05)
Hydroxylamine reacts with aspirin in aqueous solution at 25 °C predominantly through oxygen, to give O-acetylhydroxylamine as the initial product (Scheme 3). The reaction is much faster than the intramolecular general base catalysed hydrolysis of the carboxylate anion, as it is also for the CO2H form of aspirin. Both reactions are faster than expected, consistent with moderate activation and/or proton transfer catalysis of hydroxylaminolysis by both CO2- and CO2H groups. Calculations support oxygen attack as the preferred reaction, but do not permit a clear choice between mechanisms involving NH2OH and +NH3-O- as the effective nucleophile. ARKAT-USA, Inc.
Nuclear magnetic resonance study of addition-cyclization involving ethyl thioacetoacetate and α-nucleophiles
Cocivera, Michael,Basu, Soumen,Copp, Leslie,Malatesta, Vincenzo
, p. 629 - 634 (2007/10/02)
Addition of NH2NH2 or NH2OH to ethyl thioacetoacetate to form the corresponding cyclic product, 3-methylpyrazol-5-one or 3-methylisoxazol-5-one proceeds via cyclization of the carbinolamine formed by addition to the β-keto carbon, i.e., cyclization is faster than dehydration of the carbinolamine to form the imine.In contrast the corresponding carbinolamine derived from ethylacetoacetate undergoes dehydration faster than cyclization.By means of 1H nuclear magnetic resonance spectroscopy, it is possible to detect the cyclic carbinolamine as well as another transient and measure their rates of decay.Based on these results, a mechanism is proposed.
