82860-27-3Relevant articles and documents
Nitrosobenzene cross-dimerization: Structural selectivity in solution and in solid state
Biljan, Ivana,Cvjetojevic, Gorana,Smrecki, Vilko,Novak, Predrag,Mali, Gregor,Plavec, Janez,Babic, Darko,Mihalic, Zlatko,Vancik, Hrvoj
experimental part, p. 22 - 26 (2010/09/16)
Possibility of nitrosobenzenes to form dimeric molecular structures (azodioxides) is used as a model for intermolecular selectivity investigations in solution as well as in solid state. Cross-dimerization of different combinations of p- and m-substituted nitrosobenzene pairs was studied by variable temperature 1H NMR, solid-state NMR (CP MAS), IR, and ab initio calculations. It is evident that p-nitronitrosobenzene behaves nonselectively because it forms dimers with all the studied nitrosobenzene partners. In contrast, p-methoxynitrosobenzene in most cases does not form dimers. The evidence that ability to form dimers is different in solution than in the solid state can be explained by influence of molecular arrangements in the crystal lattice.
Nitrosobenzene dimerizations as a model system for studying solid-state reaction mechanisms
Vancik, Hrvoj,Simunic-Meznaric, Vesna,Mestrovic, Ernest,Halasz, Ivan
, p. 4829 - 4834 (2007/10/03)
Thermal dimerization of nitroso compounds in the solid state was investigated by using para-substituted nitrosobenzenes as model compounds. A mechanism that includes the interplay of topochemical reaction trajectories and phase transfer was proposed on the basis of FT-IR spectroscopic kinetics, time-resolved powder diffraction, and low-temperature X-ray structure determination. From shapes of the kinetic curves analyzed on the basis of the Avrami model, it was found that phase transfer could be triggered by a dimerization reaction of para-substituted nitrosobenzene to azodioxide, which, in turn, can be caused by different packing factors such as disorder in the starting nitroso monomer crystals. Since the represented model can be extended to a broad series of compounds, we propose it as a general method for investigations of solid-state reaction mechanisms.
Oxidation of Aromatic Amines with Hydrogen Peroxide Catalyzed by Cetylpyridinium Heteropolyoxometalates
Sakaue, Sigeki,Tsubakino, Takashi,Nishiyama, Yutaka,Ishii, Yasutaka
, p. 3633 - 3638 (2007/10/02)
Various substituted anilines 1 were selectively converted into the corresponsing nitrosobenzenes 2 or nitrobenzenes 3 by oxidation with aqueous hydrogen peroxide catalyzed by heteropolyoxometalates.The oxidation of anilines 1 with 35percent H2O2 catalyzed by peroxotungstophosphate (PCWP) at room temperature in chloroform under two-phase conditions afforded nitrosobenzene 2 with high selectivity.When the same reactions were carried out at higher temperature (e.g., refluxing chloroform), nitrobenzenes 3 were obtained in good yields.The oxidation of aniline (1a) with dilute H2O2 catalyzed by PCWP (2 wtpercent) in an aqueous medium produced azoxybenzene (4a) with high selectivity.Phenylazoxyalkanes 7 were prepared by the first direct cooxidation of 1a in the presence of primary aliphatic amines 6.For example, the oxidation of a 1:2 mixture of 1a and hexylamine (6b) with 35percent H2O2 (6 equiv) in the presence of PCWP produced phenylazoxyhexane (7b) along with a small amount of 4a (8percent).The reaction path for the conversion of anilines to azoxy-, nitroso-, and nitrobenzenes is described.
Oxidation of Aliphatic and Aromatic Amines with Hydrogen Peroxide Catralyzed by Peroxoheteropoly Oxometalates
Sakaue, Shigeki,Sakata, Yasuyuki,Nishiyama, Yutaka,Ishii, Yasutaka
, p. 289 - 292 (2007/10/02)
Peroxotungstophosphate (PCWP) was found to be an efficient catalyst for the oxidation of amines with 35percent H2O2 under the biphasic or homogeneous condition.Thus, primary and secondary amines were oxidized to oximes and nitrones, respectively, in good yields.Aromatic amines afforded to the corresponding nitroso compounds and/or nitrobenzenes.
