Synthesis
General procedure for the synthesis of 4-[2-(Boc-amino)ethyl]aniline from tert-butyl N-[2-(4-nitrophenyl)ethyl]carbamate: To a solution of tert-butyl N-[2-(4-nitrophenyl)ethyl]carbamate (18.7 g, 70.30 mmol) in ethanol (200 ml), a slurry of 10% palladium-carbon (2 g) was added. Water (10 ml) was subsequently added. Anhydrous ammonium formate (44.3 g, 703 mmol) was added to the reaction system at 80°C. Triethylamine (90 ml) was added slowly. After addition, the mixture was stirred at 80 °C for 1 hour. After completion of the reaction, the mixture was allowed to cool to room temperature, filtered and concentrated under vacuum. The residue was diluted with water and extracted twice with dichloromethane. The combined organic layers were washed with water, dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure to afford the target product 4-[2-(Boc-amino)ethyl]aniline as a yellow oil (13.5 g, 81% yield).
References
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[3] Patent: WO2008/13997, 2008, A2. Location in patent: Sheet 9
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[5] Patent: WO2006/40179, 2006, A1. Location in patent: Page/Page column 99