66635-96-9Relevant academic research and scientific papers
Peroxomonophosphoric Acid Oxidations. VI. Kinetics and Mechanism of Oxidation of 3-Aminopyridine
Mahapatro, Surendra Nath,Panda, Abhina Kumar,Panigrahi, Ganesh Prasad
, p. 2507 - 2510 (1981)
The oxidation of 3-aminopyridine to 3,3'-azoxypyridine by peroxomonophosphoric acid (PMPA) is a total second order reaction: first order each in peroxomonophosphoric acid and 3-aminopyridine at constant acidity.The observed pH-rate profile has been rationalized invoking various PMPA species, protonated and unprotonated forms of 3-aminopyridine as the reactive species and their reactivities have been estimated.Interestingly, 2-aminopyridine is not oxidized in the pH-range where the oxidation of 3-aminopyridine is facile.
Modulating the catalytic behavior of non-noble metal nanoparticles by inter-particle interaction for chemoselective hydrogenation of nitroarenes into corresponding azoxy or azo compounds
Liu, Lichen,Concepción, Patricia,Corma, Avelino
, p. 312 - 323 (2018/12/11)
Aromatic azoxy compounds have wide applications and they can be prepared by stoichiometric or catalytic reactions with H2O2 or N2H4 starting from anilines or nitroarenes. In this work, we will present the direct chemoselective hydrogenation of nitroarenes with H2 to give aromatic azoxy compounds under base-free mild conditions, with a bifunctional catalytic system formed by Ni nanoparticles covered by a few layers of carbon (Ni@C NPs) and CeO2 nanoparticles. The catalytic performance of Ni@C-CeO2 catalyst surpasses the state-of-art Au/CeO2 catalyst for the direct production of azoxybenzene from nitrobenzene. By means of kinetic and spectroscopic results, a bifunctional mechanism is proposed in which, the hydrogenation of nitrobenzene can be stopped at the formation of azoxybenzene with >95% conversion and >93% selectivity, or can be further driven to the formation of azobenzene with >85% selectivity. By making a bifunctional catalyst with a non-noble metal, one can achieve chemoselective hydrogenation of nitroarenes not only to anilines, but also to corresponding azoxy and azo compounds.
An easy access to aromatic azo compounds under ultrasound/microwave irradiation
Cravotto, Giancarlo,Boffa, Luisa,Bia, Marco,Bonrath, Werner,Curini, Massimo,Heropoulos, Georgios A.
, p. 2605 - 2608 (2008/09/16)
Chemoselective reduction of nitroarenes to azo and azoxy compounds was easily achieved using zinc powder and ammonium chloride in DMF or DMF-water (95:5) under high intensity ultrasound (US) or microwave (MW) irradiation, separately or combined. When carried out under conventional heating the reaction required much higher temperatures and gave lower yields. The addition of a small amount of water caused a dramatic increase in the reactivity, permitting the reduction of hindered nitroarenes at the expense of selectivity. A novel reactor for combined US/MW irradiation was employed which demonstrated additional beneficial effects. Georg Thieme Verlag Stuttgart.
