139-24-2Relevant articles and documents
Preparation of niobium or tantalum complex and application of niobium or tantalum complex in catalyzing aromatic amine to generate oxidized azobenzene compound
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Paragraph 0072-0075, (2021/11/03)
The invention provides a preparation method of niobium or tantalum complex and an application of the niobium or tantalum complex in catalyzing aromatic amine to generate an oxidized azobenzene compound. The preparation method of the complex comprises A hydration oxide preparation, @timetime@ niobium oxide or tantalum oxide and strong base in 300 - 800 °C melting calcination 2 - 8h, adding water to dissolve and filter, and then adjusting pH through 4-6, suction filtration and drying. The B complex is prepared by mixing a hydrated oxide with a molar ratio 10-25: 1 with hydrogen peroxide, adding an organic acid and a cationic precursor after clarifying the solution, and evaporating and drying to obtain a niobium complex or a tantalum complex. The molar ratio @timetime@: 1-3. In the method for synthesizing the oxidized azobenzene compound by using niobium or tantalum complex as a catalyst, ethanol is used as a solvent, hydrogen peroxide is used as an oxidant, niobium complex or tantalum complex is used as a catalyst, and the addition amount is ppm.
SO2F2-mediated oxidation of primary and tertiary amines with 30% aqueous H2O2 solution
Liao, Xudong,Zhou, Yi,Ai, Chengmei,Ye, Cuijiao,Chen, Guanghui,Yan, Zhaohua,Lin, Sen
supporting information, (2021/11/01)
A highly efficient and selective oxidation of primary and tertiary amines employing SO2F2/H2O2/base system was described. Anilines were converted to the corresponding azoxybenzenes, while primary benzylamines were transformed into nitriles and secondary benzylamines were rearranged to amides. For tertiary amine substrates quinolines, isoquinolines and pyridines, their oxidation products were the corresponding N-oxides. The reaction conditions are very mild and just involve SO2F2, amines, 30% aqueous H2O2 solution, and inorganic base at room temperature. One unique advantage is that this oxidation system is just composed of inexpensive inorganic compounds without the use of any metal and organic compounds.
Preparation of azoxy benzene (by machine translation)
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Paragraph 0029; 0036, (2020/05/21)
[A] good workability and safety, cost, and, efficient production of the azoxy benzene azoxy benzene can be produced. [Solution] nitrobenzene ones, having the photocatalytic function with a dye, a reducing agent such as a fluorine resin or a transparent resin material is a mixed solution of 1 mm in diameter are inserted into the tube 4 does not inhibit the reaction, 4 LED lamp 5 emits visible from the outside of the tube moves within the tube 4 is provided with visible light within the tube 4 by a photocatalyst reaction mixed solution so as to obtain azoxy benzene compounds. Figure 2 [drawing] (by machine translation)
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.
Room temperature catalytic reduction of nitrobenzene to azoxybenzene over one pot synthesised reduced graphene oxide decorated with Ag/ZnO nanocomposite
Paul, Bappi,Vadivel,Yadav, Nishant,Dhar, Siddhartha Sankar
, p. 71 - 75 (2019/03/13)
We report herein, a one-pot synthetic route for the synthesis of reduced graphene oxide decorated Ag/ZnO nanocomposite and studied its catalytic activity as simple, recyclable and efficient catalyst for one-pot conversion of nitrobenzene to azoxybenzene. It was observed that 5–10 nm Ag-nanoparticles supported on 40–60 nm ZnO nanorod decorated on reduced graphene oxide was formed with a silver loading of 1.6 wt%. The effect of different reaction parameters were investigated and studied in detail. A nitrobenzene conversion of 96% with 98% selectivity of azoxybenzene was achieved without the use of any external additives.
Controllable synthesis of azoxybenzenes and anilines with alcohol as the reducing agent promoted by KOH
Wei, Rui Ping,Shi, Feng
, p. 688 - 696 (2019/02/16)
Nitrobenzene and its derivatives can be selectively reduced to the corresponding azoxybenzene and aniline compounds with alcohols as the hydrogen source and KOH as the promoter only by simple changes of reaction conditions.
Catalytic Selective Oxidative Coupling of Secondary N-Alkylanilines: An Approach to Azoxyarene
Ke, Lei,Zhu, Guirong,Qian, Hui,Xiang, Guangya,Chen, Qin,Chen, Zhilong
supporting information, p. 4008 - 4013 (2019/06/04)
Azoxyarenes are among important scaffolds in organic molecules. Direct oxidative coupling of primary anilines provides a concise fashion to construct them. However, whether these scaffolds can be prepared from secondary N-alkylanilines is not well explored. Here, we present a catalytic selective oxidative coupling of secondary N-alkylaniline to afford azoxyarene with tungsten catalyst under mild conditions. In addition, azoxy can be viewed as a bioisostere of alkene and amide. Several "azoxyarene analogues" of the corresponding bioactive alkenes and amides showed comparable promising anticancer activities.
Nb2O5 supported on mixed oxides catalyzed oxidative and photochemical conversion of anilines to azoxybenzenes
De Carvalho, Gustavo Senra Gon?alves,Chagas, Luciano Honorato,Fonseca, Carla Grijó,De Castro, Pedro P?ssa,Sant'Ana, Ant?nio Carlos,Leit?o, Alexandre Amaral,Amarante, Giovanni Wilson
supporting information, p. 5863 - 5871 (2019/04/17)
The synthesis of novel supported niobium oxide catalysts and their application for aniline conversion to azoxybenzenes is described. The catalysts were successfully prepared by thermal decomposition of layered double hydroxides (LDHs), containing M2+ (M = Mg2+ and/or Zn2+) and Al3+ as layer cations, followed by niobium oxide incorporation employing the wetness impregnation method. These catalysts were fully characterized by both experimental techniques and theoretical calculations, and then successfully applied to the selective conversion of anilines into azoxybenzene derivatives, with up to 98% conversion and 92% isolated yield in the presence of violet light. Control experiments and DFT calculations revealed that the catalyst has a dual role in this transformation, acting both as a Lewis acid in the oxidative step and as a photocatalyst in the dimerization of the nitrosobenzene intermediate.
Low-temperature catalytic oxidation of aniline to azoxybenzene over an Ag/Fe2O3 nanoparticle catalyst using H2O2 as an oxidant
Paul, Bappi,Sharma, Sachin K.,Adak, Shubhadeep,Khatun, Rubina,Singh, Gurmeet,Das, Dipak,Joshi, Vedant,Bhandari, Sahil,Dhar, Siddhartha Sankar,Bal, Rajaram
, p. 8911 - 8918 (2019/06/18)
An in situ modified hydrothermal synthesis of Ag/Fe2O3 nanoparticles (NPs) and studies of their catalytic activity as a simple, eco-friendly and recyclable catalyst for one-pot conversion of aniline to azoxybenzene were performed. The as-synthesized nanostructured material was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), SEM-mapping, temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption isotherms (BET), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), ultraviolet-visible spectroscopy (UV-vis) and vibrating sample magnetometer spectroscopy (VSM). The most active and recyclable catalyst with 2-5 nm diameters of the metallic Ag particles supported on 10-50 nm Fe2O3 nanoparticles was formed with a silver loading of 1.8 wt%. A high turnover number of ～592 was achieved with 92% conversion of aniline and 94% selectivity towards the target product azoxybenzene under atmospheric conditions. The effects of various reaction parameters including the reaction time, temperature and substrate to H2O2 molar ratio were screened and studied in detail. The results reveal the role of a synergistic effect between the surface Ag nanoparticles and Fe2O3 nanospheres for high catalytic activity.
Method for synthesizing oxidized azo compound through selective oxidation of aromatic amine
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Paragraph 0027-0051; 0052-0055, (2019/02/13)
The invention discloses a method for synthesizing an oxidized azo compound through selective oxidation of an aromatic amine, wherein an aromatic amine is used as a raw material, hydrogen peroxide is used as an oxidizing agent, a titanium-silicon molecular sieve or a metal modified titanium-silicon molecular sieve is used as a catalyst, and the aromatic amine is subjected to selective catalytic oxidation to prepare the corresponding oxidized azobenzene compound. According to the present invention, the method has advantages of environmental protection, good selectivity, high product yield, easyseparation and recycling of the catalyst, simple instrument required by the reaction, and easy operation.
