54659-85-7Relevant articles and documents
The Continuous Synthesis of 2-(2'-Hydroxy-5'-Methylphenyl)Benzotriazole over Cu/γ-Al2O3
Yan,Si,Tao,Liu,Wang,Li
, p. 635 - 641 (2019/10/19)
Abstract: The samples of 20% Cu/γ-Al2O3, 20% Co/γ-Al2O3 and 20% Ni/γ-Al2O3 were prepared as hydrogenation catalysts for continuous synthesis of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole. The best yield (86.62%) was afforded by the 20% Cu/γ-Al2O3 catalyst. The characterizations results obtained for the 20% Cu/γ-Al2O3 sample confirmed that Cu particles are evenly distributed over the surface of γ-Al2O3. A reduction of acid sites in the catalyst favored the selectivity to 2-(2'-hydroxy-5'-methylphenyl)benzotriazole. Furthermore, the effect of Cu content, reaction temperature, hydrogen pressure and liquid hourly space velocity was studied. Finally, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole in 86.62% yield was attained under the optimized conditions.
Reductive cyclization of 2-nitro-2′-hydroxy-5′-methylazobenzene to benzotriazole over K-doped Pd/γ-Al2O3
Wang, Bowei,Si, Leilei,Yuan, Yanyan,Li, Yang,Chen, Ligong,Yan, Xilong
, p. 16766 - 16771 (2016/02/20)
A series of Pd/γ-Al2O3 catalysts modified by potassium salts were prepared and evaluated in the reductive cyclization of 2-nitro-2′-hydroxy-5′-methylazobenzene without additional base. These solid base-hydrogenation bifunctional catalysts were characterized and the results demonstrated that potassium salts could have an important impact on the properties and catalytic performance of Pd/γ-Al2O3.
Liquid-phase hydrogenation of 2-nitro-2′-hydroxy-5′- methylazobenzene on raney nickel at low temperatures
Zuenko,Nemtseva,Lefedova,Nikolaev
, p. 877 - 881 (2007/10/03)
The character of changes in the concentrations of intermediate products at the initial stage of the hydrogenation of 2-nitro-2′-hydroxy-5′- methylazobenzene (I) on Raney nickel at 275 K and the reasons for their dependence on the composition of the solvent were determined. The smallest amount of I and the largest yield of substituted benzotriazole N-oxide were obtained when the reaction was conducted in a 2-propanol-water solvent containing sodium hydroxide. Conversely, the addition of acids to the solvent sharply increased the yield of the nitrohydrazo derivative. The selectivity of hydrogenation with respect to the substituted benzotriazole was determined by the ratio between the rates of hydrogenation of the nitro and azo groups in the initial compound and intramolecular homogeneous rearrangements of intermediate products.
