A. Preparation of loaded nickel catalysts
In a 25 mL round-bottomed flask, 4.75 g of nickel chloride hexahydrate was dissolved in 15 mL of deionized water, 20 g of neutral alumina was added, sonicated and dried overnight. Weigh 0.3 g of sodium borohydride and prepare 800 mL of 0.01 mol/L solution. Add 5 g of precursor to a 1 L flask, add mechanical stirring, and slowly add aqueous sodium borohydride solution, filter the product after the reaction is complete and dry to obtain the desired catalyst.
B. Synthesis of 2,2'-(ethane-1,2-diyl)diphenylamine
In a 10 mL round bottom flask, 300 mg of 2-nitrobenzyl chloride, 300 mg of catalyst, 2 mL of deionized water and 2 mL of 60% hydrazine hydrate were slowly added dropwise with magnetic stirring until complete incorporation and stirred continuously for 20 min at room temperature to obtain the reaction mixture. The reaction mixture was extracted with ethyl acetate and analyzed by GC-MS to give about 51% yield of the target product. The catalyst was washed three times each with water and ethanol and dried for reuse.
