Synthesis
The general procedure for the synthesis of 5-Boc-amino-1-pentyl bromide from 5-(N-tert-butoxycarbonylamino)-1-pentanol was as follows: 5-(N-tert-butoxycarbonylamino)-1-pentanol (3.00 g, 14.8 mmol) was dissolved in THF (41 mL) and cooled to 0 °C. CBr4 (7.34 g, 22.1 mmol) and PPh3 (5.96 g, 22.7 mmol) were added sequentially. After stirring at 0 °C for 1 h, CBr4 (2.55 g, 7.68 mmol) and PPh3 (2.17 g, 8.27 mmol) were added. The reaction mixture was continued to be stirred at room temperature for 14 hours. After completion of the reaction, it was diluted with 30% EtOAc/hexane, filtered and washed with the same ratio of EtOAc/hexane. The filtrates were combined, concentrated in vacuum and the residue was purified by silica gel column chromatography (eluent: CHCl3/hexane, gradient from 20% to 100%) to afford the target product tert-butyl N-(5-bromopentyl)carbamate (3.2 g, 81% yield).
References
[1] ACS Medicinal Chemistry Letters, 2017, vol. 8, # 5, p. 510 - 515
[2] ACS Medicinal Chemistry Letters, 2015, vol. 6, # 11, p. 1156 - 1161
[3] Journal of Medicinal Chemistry, 2018, vol. 61, # 17, p. 7892 - 7901
[4] Patent: WO2012/177782, 2012, A1. Location in patent: Page/Page column 87
[5] Journal of Organic Chemistry, 1983, vol. 48, p. 24
