Ethyl Acetate → 4-(2,2,2-Trifluoroethyl)piperazin-1-amine

To a suspension of lithium aluminum hydride (2.22 g, 58.5 mmol) in tetrahydrofuran (100 mL) that cooled with ice bath, a solution of 1-nitroso-4-(2,2,2-trifluoroethyl)piperazine (5.43 g, 27.5 mmol) in tetrahydrofuran (10 mL) was added dropwise and the reaction mixture was allowed to warm to ambient temperature, then stirred for 5 days. The reaction mixture was cooled with ice bath, ethyl acetate was added until cease bubbling up, and water (2.1 mL) was added then the mixture was stirred for 20 min. To this mixture, 15% w/v sodium hydroxide solution (2.1 mL) and water (6.3 mL) were added, then the suspension mixture was allowed to warm to ambient temperature and then the mixture was stirred vigorously for 1 h. Magnesium sulfate was added to the mixture and stirred for a while, then the suspension was filtered. The filtrate was concentrated to afford 4-(2,2,2-trifluoroethyl)piperazine-1-amine as oil (4.72 g, y. 94%).