The Continuous Synthesis of 2-(2'-Hydroxy-5'-Methylphenyl)Benzotriazole over Cu/γ-Al2O3

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.