1092522-02-5

The general procedure for the synthesis of tert-butyl (4-aminophenyl)methylcarbamate from tert-butyl methyl(4-nitrophenyl)carbamate was as follows: to a mixed solution of THF/MeOH/H2O (150 mL/40 mL/80 mL) containing methyl tert-butyl(4-nitrophenyl)carbamate (8.3 g, 32.9 mmol) was added iron powder (9.4 g), 168 mmol, and ammonium chloride (18 g, 337 mmol), in sequence. (168 mmol) and ammonium chloride (18 g, 337 mmol). The reaction mixture was heated and stirred at 50 °C for 4 h under nitrogen protection. After completion of the reaction, it was cooled to room temperature and filtered through a diatomaceous earth pad to remove solid impurities. The filtrate was extracted with ethyl acetate (100 mL x 3), and the organic phases were combined, washed sequentially with water and saturated saline, and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure to afford the target product tert-butyl (4-aminophenyl)methylcarbamate (7.3 g, 100% yield) as a yellow solid. The product was analyzed by LC-MS (ESI) with m/z (M + 1) of 223.

[1] Patent: US2013/197014, 2013, A1. Location in patent: Paragraph 0734; 0735
[2] Bioorganic and Medicinal Chemistry, 2008, vol. 16, # 23, p. 10034 - 10042
[3] Patent: EP2409977, 2012, A1. Location in patent: Page/Page column 124
[4] ACS Medicinal Chemistry Letters, 2015, vol. 6, # 2, p. 112 - 116
[5] Patent: , 2016, . Location in patent: Paragraph 0039; 0077; 0078; 0079