A Reusable FeCl3•6H2O/Cationic 2,2′-Bipyridyl Catalytic System for Reduction of Nitroarenes in Water

The association of a commercially-available iron (III) chloride hexahydrate (FeCl3 center dot 6H(2)O) with cationic 2,2 '-bipyridyl in water was proven to be an operationally simple and reusable catalytic system for the highly-selective reduction of nitroarenes to anilines. This procedure was conducted under air using 1-2 mol% of catalyst in the presence of nitroarenes and 4 equiv of hydrazine monohydrate (H2NNH2 center dot H2O) in neat water at 100 degrees C for 12 h, and provided high to excellent yields of aniline derivatives. After separation of the aqueous catalytic system from the organic product, the residual aqueous solution could be applied for subsequent reuse, without any catalyst retreatment or regeneration, for several runs with only a slight decrease in activity, proving this process eco-friendly.

Automated summary

The combination of commercially-available iron (III) chloride hexahydrate and cationic 2,2'-bipyridyl in water has been proven to be an operationally simple and reusable catalytic system for the highly-selective reduction of nitroarenes to anilines. This process, conducted under air at 100 degrees C for 12 hours, shows high efficiency and eco-friendliness.