Synthesis
Tert-butyl cis-3-azido cyclobutylcarbamate (15.00 g, 70.7 mmol) was used as a feedstock and mixed with 10 wt% palladium/activated carbon catalyst (dry basis) in a 1000 mL three-neck flask. The system was flushed with N2 and sealed with methanol (200 mL) and 2 M ammonia (3.76 mL, 35.3 mmol, Sigma-Aldrich Chemical Company, Inc.). The flask was evacuated and filled with hydrogen (balloon supply). The reaction mixture was stirred at room temperature for 18 hours and subsequently filtered. The filtrate was concentrated under reduced pressure to afford tert-butyl cis-3-amino-1-cyclobutylcarbamate (11.1 g, 59.6 mmol, 84% yield), which could be used in subsequent steps without further purification.
References
[1] Journal of Organic Chemistry, 2010, vol. 75, # 17, p. 5941 - 5952
[2] Patent: US2013/225552, 2013, A1. Location in patent: Paragraph 0990
