Abstract:

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.

Key words: Poly(ethylene glycol), Ionic liquid, Thermoregulated biphase, Nitroarene, Reduction