General procedure for the synthesis of 3,5-difluorobenzylamine from 3,5-difluorobenzonitrile: 3,5-difluorobenzonitrile (4 g, 28.8 mmol) was added to a nickel Nguyen Nai slurry pre-washed with methanol, which had been treated with ammonia (100 ml) saturated methanol solution. The reaction mixture was shaken under 50 psi hydrogen pressure for 1.5 hours. Upon completion of the reaction, the reaction mixture was filtered and the filtrate evaporated. The residue was dissolved in ethyl acetate and subsequently extracted with 3N hydrochloric acid solution. The acidic aqueous phase was alkalized with 50% sodium hydroxide solution and extracted again with ethyl acetate. The organic phases were combined and concentrated by drying with anhydrous sodium sulfate to give 3.0 g (74% yield) of 3,5-difluorobenzylamine, the product was a yellow oil, which needed to be stored under nitrogen protection.
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