71297-97-7

Upstream product

• 99-08-1 1-methyl-3-nitrobenzene 
• 620-25-7 N-(3-methylphenyl)hydroxylamine 
• 61563-95-9 N-Hydroxy-m-acetoacetanilid 
• 136696-42-9 2-acetyl-3,4-dimethylthiazolium triflate 
• 7732-18-5 water 
• 64-17-5 ethanol 
• 141-52-6 sodium ethanolate 
• 302-01-2 hydrazine 
• 7647-01-0 hydrogenchloride 
• 123-91-1 1,4-dioxane 
• 623-11-0 1-methyl-4-nitrosobenzene 
• 620-26-8 3-nitrosotoluene 
• 63526-65-8 cis-3,3'-dimethylazobenzene 
• 108-44-1 1-amino-3-methylbenzene 

Downstream Products

• 588-04-5 3,3'-dimethylazobenzene 
• 621-26-1 3,3'-dimethylhydrazobenzene 
• 71297-97-7 N,N'-bis(3-methylphenyl)-diazene N-oxide 
• 76216-35-8 2-Methyl-4-m-tolylazo-phenol 

Relevant academic research and scientific papers

Zr(OH)4-Catalyzed Controllable Selective Oxidation of Anilines to Azoxybenzenes, Azobenzenes and Nitrosobenzenes

The selective oxidation of aniline to metastable and valuable azoxybenzene, azobenzene or nitrosobenzene has important practical significance in organic synthesis. However, uncontrollable selectivity and laborious synthesis of the expensive required catalysts severely hinders the uptake of these reactions in industrial settings. Herein, we have pioneered the discovery of Zr(OH)4 as an efficient heterogeneous catalyst capable of the selective oxidation of aniline, using either peroxide or O2 as oxidant, to selectively obtain various azoxybenzenes, symmetric/unsymmetric azobenzenes, as well as nitrosobenzenes, by simply regulating the reaction solvent, without the need for additives. Mechanistic experiments and DFT calculations demonstrate that the activation of H2O2 and O2 is primarily achieved by the bridging hydroxyl and terminal hydroxyl groups of Zr(OH)4, respectively. The present work provides an economical and environmentally friendly strategy for the selective oxidation of aniline in industrial applications.

Preparation of niobium or tantalum complex and application of niobium or tantalum complex in catalyzing aromatic amine to generate oxidized azobenzene compound

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.

Selective Oxidation of Anilines to Azobenzenes and Azoxybenzenes by a Molecular Mo Oxide Catalyst

Aromatic azo compounds, which play an important role in pharmaceutical and industrial applications, still face great challenges in synthesis. Herein, we report a molybdenum oxide compound, [N(C4H9)4]2[Mo6O19] (1), catalyzed selective oxidation of anilines with hydrogen peroxide as green oxidant. The oxidation of anilines can be realized in a fully selectively fashion to afford various symmetric/asymmetric azobenzene and azoxybenzene compounds, respectively, by changing additive and solvent, avoiding the use of stoichiometric metal oxidants. Preliminary mechanistic investigations suggest the intermediacy of highly active reactive and elusive Mo imido complexes.

Shape-dependent reactivity and chemoselectivity of nanogold towards nitrophenol reduction in water

Although the catalytic activity of nano-gold surfaces for the reduction of nitro compounds has been known, the effect of their shape has been rarely evaluated. Here, the synthesis, characterization, and application of both gold nanoworms (GNW) and gold nanospheres (GNS) are described. Both GNW and GNS were characterized using SEM, TEM, UV–Vis, FTIR, and XPS spectroscopy. The catalytic efficiency of GNW with an average dimensions of 2 × 250 nm (D × L) towards the hydrogenation of nitrophenol, a pollutant present in industrial wastewater, is higher (TOF 3675 h?1) than that of spherical GNS (10 ± 1 nm), for which TOF is 1838 h?1 in water using NaBH4 as the reductant. The selectivity of 4-aminophenol is 100% for both GNS and GNW.

Tandem selective reduction of nitroarenes catalyzed by palladium nanoclusters

We report a catalytic tandem reduction of nitroarenes by sodium borohydride (NaBH4) in aqueous solution under ambient conditions, which can selectively produce five categories of nitrogen-containing compounds: anilines, N-aryl hydroxylamines, azoxy-, azo- and hydrazo-compounds. The catalyst is in situ-generated ultrasmall palladium nanoclusters (Pd NCs, diameter of 1.3 ± 0.3 nm) from the reduction of Pd(OAc)2 by NaBH4. These highly active Pd NCs are stabilized by surface-coordinated nitroarenes, which inhibit the further growth and aggregation of Pd NCs. By controlling the concentration of Pd(OAc)2 (0.1-0.5 mol% of nitroarene) and NaBH4, the water/ethanol solvent ratio and the tandem reaction sequence, each of the five categories of N-containing compounds can be obtained with excellent yields (up to 98%) in less than 30 min at room temperature. This tunable catalytic tandem reaction works efficiently with a broad range of nitroarene substrates and offers a green and sustainable method for the rapid and large-scale production of valuable N-containing chemicals.

Green and highly efficient approach for the reductive coupling of nitroarenes to azoxyarenes using the new mesoporous Fe3O4@SiO2@Co–Zr–Sb catalyst

Efficient, green, simple and environmentally friendly approach for the straightforward reductive coupling of nitroarenes to the corresponding azoxyarenes has been developed in the presence of Fe3O4@SiO2@Co–Zr–Sb as a novel recyclable nanocatalyst. The Co–Zr–Sb trimetallic nanoparticles immobilized on silica-layered magnetite have been prepared by the co-precipitation method. The mesoporous catalyst has been characterized by FT-IR, SEM, EDX, VSM, TEM and XRD analyses. The chemoselective hydrogenation of nitrobenzenes was carried out successfully in refluxing water to afford the corresponding azoxybenzenes within 2–10?min in good to high yields. The reusability of the heterogeneous nanocatalyst has also been studied using the FT-IR and SEM analyses. The catalyst was utilized four times in sequential runs without significant loss of activity. The current research includes remarkable advantages of short reaction times, absence of hazardous organic solvents, mild reaction conditions, high yields, using water as a green solvent and the ability to utilize the recyclable nanomagnetic catalyst.

Palladium Nanoparticles on Silica Nanospheres for Switchable Reductive Coupling of Nitroarenes

Abstract: In this study, we synthesized a robust and sustainable Pd/SiO2 nanospheres catalyst. Further, its catalytic activity was demonstrated for the direct reductive coupling of nitroarenes under mild conditions. While the reaction with Pd nanoparticles on other supporting materials such as modified carbon materials and TiO2, under similar conditions, resulted formation of amines exclusively. Therefore, it was confirmed that the SiO2 was found to be the best supporting material towards the selective reductive coupling of nitroarenes. Also, the catalyst could be recycled up to five cycles with a marginal loss of product yield ( 2% yield). Graphic Abstract: [Figure not available: see fulltext.].

Method for synthesizing oxidized azo compound through selective oxidation of aromatic amine

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.

Low-temperature catalytic oxidation of aniline to azoxybenzene over an Ag/Fe2O3 nanoparticle catalyst using H2O2 as an oxidant

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.

Niobium oxide prepared through a novel supercritical-CO2-assisted method as a highly active heterogeneous catalyst for the synthesis of azoxybenzene from aniline

High-surface area Nb2O5 nanoparticles were synthesised by a novel supercritical-CO2-assisted method (Nb2O5-scCO2) and were applied for the first time as a heterogeneous catalyst in the oxidative coupling of aniline to azoxybenzene using the environmentally friendly H2O2 as the oxidant. The application of scCO2 in the synthesis of Nb2O5-scCO2 catalyst resulted in a significantly enhanced catalytic activity compared to a reference catalyst prepared without scCO2 (Nb2O5-Ref) or to commercial Nb2O5. Importantly, the Nb2O5-scCO2 catalyst achieved an aniline conversion of 86% (stoichiometric maximum of 93% with the employed aniline-to-H2O2 ratio of 1?:?1.4) with an azoxybenzene selectivity of 92% and with 95% efficiency in H2O2 utilisation in 45 min without requiring external heating (the reaction is exothermic) and with an extremely low catalyst loading (weight ratio between the catalyst and substrate, Rc/s = 0.005). This performance largely surpasses that of any other heterogeneous catalyst previously reported for this reaction. Additionally, the Nb2O5 catalyst displayed high activity also for substituted anilines (e.g. methyl or ethyl-anilines and para-anisidine) and was reused in consecutive runs without any loss of activity. Characterisation by means of N2-physisorption, XRD, FTIR and TEM allowed the correlation of the remarkable catalytic performance of Nb2O5-scCO2 to its higher surface area and discrete nanoparticle morphology compared to the aggregated larger particles constituting the material prepared without scCO2. A catalytic test in the presence of a radical scavenger proved that the reaction follows a radical pathway.