64583-54-6Relevant academic research and scientific papers
An Environmentally Sustainable Mechanochemical Route to Hydroxamic Acid Derivatives
Mocci, Rita,De Luca, Lidia,Delogu, Francesco,Porcheddu, Andrea
, p. 3135 - 3144 (2016/10/09)
An operationally simple, and cost efficient conversion of carboxylic acids into hydroxamic acid derivatives via a high-energy mechanochemical activation is presented. This ball milling methodology was applied to a wide variety of carboxylic acids dramatically improving purification issues associated with this class of molecules, which still remain one of the main bottlenecks of classical methodologies. (Figure presented.).
New calcium antagonists: Synthesis, X-ray analysis, and smooth muscle relaxing effect of 3-[O-(benzyl-substituted)-oximino-ethers]-hexahydroazepin-2,3-diones
El From, Hayat,Pera, Marie-Helene,Leclerc, Gerard,Tranqui, Duc,Corompt, Emmanuelle,Bessard, Germain,Devillier, Philippe
, p. 1655 - 1663 (2007/10/03)
A series of new Z and E 3-[O-(benzyl-substituted)-oximino-ether]-hexahydroazepin-2,3-diones was prepared from the corresponding hexahydroazepin-2,3-diones and examined as smooth muscle relaxants. E and Z structures were assigned by NMR analysis and confirmed for 16 (E and Z) by an X-ray diffraction using synchrotron radiations. The nitrobenzyl derivative 16 was the most potent in vitro as relaxant of rat trachea precontracted with acetylcholine. The E isomer 16b was more potent than the Z isomer 16a. E isomer 16b is more potent than aminophylline to relax both rat trachea and human bronchus.This derivative acts mainly by inhibiting cellular infux of extracellular calcium since it inhibits potently and dose-dependently the contractions of rat trachea to high concentrations of KCl and to CaCl2 in a depolarizing medium. It appears to act weakly by inducing cGMP and cAMP synthesis. Moreover, its relaxing activity is not related to an inhibition of phosphodiesterases, to opening of potassium channels or to induction of prostaglandin synthesis. Therefore, 16b appears to work mainly as a potent calcium antagonist. (C) 1999 Elsevier Science Ltd.
Reactive Intermediates from the Solvolysis of Mutagenic O-Alkyl N-Acetoxybenzohydroxamates
Bonin, Antonio M.,Glover, Stephen A.,Hammond, Gerard P.
, p. 1173 - 1180 (2007/10/02)
Mutagenic O-(para-substituted benzyl) N-acetoxybenzohydroxamates undergo acid-catalysed solvolysis in aqueous acetonitrile but three is a change in mechanism from AA11 to E1 on going from para electron-withdrawing substituents to para +M electron-donating groups.The former permit the formation of a discrete nitrenium ion intermediate whereas the latter promote a concerted elimination of a resonance stabilized benzyl carbocation.
Evidence for the Formation of Nitrenium Ions in the Acid-catalysed Solvolysis of Mutagenic N-Acetoxy-N-Alkoxybenzamides
Campbell, John J.,Glover, Stephen A.,Hammond, Gerard P.,Rowbottom, Colleen A.
, p. 2067 - 2080 (2007/10/02)
In aqueous acetonitrile, N-acetoxy-N-alkoxybenzamides undergo acid-catalysed solvolysis by the AAl1 mechanism to give acetic acid and nitrenium ions.This is indicated by an inverse dependence of the acid-independent rate constant, kH, upon the activity of water, a solvent kinetic isotope effect of 0.44 and positive Σ(excit.) values.In addition, relief of steric compression at the nitrogen enhances the rate of solvolysis.Hammett correlations with ?+ substituent constants were found for the rates of solvolysis of para-substituted-N-acetoxy-N-butoxybenzamides and N-acetoxy-N-(para-substituted benzyloxy) benzamides.This fact and the low ρ-values of -1.35 and -1.56, respectively, are indicative of a strong build-up of positive charge in the transition state which has both nitrenium ion and oxonium ion character and is in accordance with computed molecular-orbital properties of N-alkoxynitrenium ions.Greater levels of mutagenicity have been measured for those compounds which are more readily solvolysed to nitrenium ions.
Reactions of N-Acyl-O-arylhydroxylamines: Part IV - Preparation of Some N-Arylsulphonyl-O-arylhydroxylamines
Singha, A. S.,Misra, B. N.
, p. 361 - 363 (2007/10/02)
A number of N-arylsulphonyl-O-alkylhydroxylamines (III) have been prepared by condensing appropriate alkoxyamines with arylsulphonyl chlorides in the presence of a base.The alkoxyamines have been obtained from the corresponding alkoxyamine hydrochlorides or hydrobromides (II) which in turn have been prepared by the hydrolysis of appropriate N-benzoyl-O-alkylhydroxylamines (I) with ethanolic hydrogen chloride or hydrogen bromide.The structure assignments of III are based on elemental analyses, chemical reaction and spectral (IR, PMR) data.
