PEG1000-DIL/甲苯温控两相体系中硝基芳烃的还原反应

研究了PEG1000-DIL/甲苯温控体系中硝基芳烃的还原反应.考察了催化加氢、水合肼/FeCl3.6H2O和水合肼/Fe5HO8.4H2O等3种还原体系,发现水合肼/Fe5HO8.4H2O在PEG1000-DIL/甲苯温控体系中具有很高的催化活性,将其用于12种硝基芳烃的还原反应,产率最高可达99%.该催化体系重复使用3次后产率无明显变化,用于卤代硝基苯类化合物的还原可以有效防止脱卤副反应的发生.

Reduction of Nitroarenes in PEG1000-DIL/Toluene Thermoregulated Biphasic System

Anilines are important and basic organic chemicals and usually prepared by reduction of corresponding nitrobezenes. In this work, a thermoregulated PEG1000-DIL/toluene biphasic system was applied in the synthesis of anilines by reduction of nitrobezenes. The palladium catalyzed reduction with hydrogen, the FeCl3·6H2O and Fe5HO8·4H2O catalyzed reduction with hydrazine hydrate were investigated. The results indicated that the Fe5HO8·4H2O presented the highest catalytic activity when PEG1000-DIL/toluene system was used as the reaction media. Twelve anilines were obtained with excellent yield of up to 99% by reduction of corresponding nitrobenzenes with hydrazine hydrate in presence of Fe5HO8·4H2O. Furthermore, the catalyst and PEG1000-DIL/toluene system could be recycled for three times without any obvious activity loss. Another noticeable advantage is that no reduction-dehalogenation side reaction was detected using this catalytic system.