Synthesis
General procedure for the synthesis of N-Cbz-3-bromoethylamine from 2-bromoethylamine hydrobromide and benzyl chloroformate: 2-bromoethylamine hydrobromide (12.000 g; 58.56 mmol; 1.0 eq.), which was cooled to 0 °C, was dissolved in dioxane (60 ml), and an aqueous 1 M NaOH solution (117.2 ml; 117.20 mmol; 2.0 equivalent), followed by dropwise addition of benzyl chloroformate (8.4 ml; 58.8 mmol; 1.0 eq.) for a controlled period of 10 min. The reaction mixture was continued to be stirred at 0 °C for 10 min under nitrogen protection, then raised to room temperature and stirred for 13 hours. After completion of the reaction, ether (300 ml) was added for extraction and the organic layer was washed with deionized water (75 ml) and dried over anhydrous sodium sulfate. The desiccant was removed by filtration and the filtrate was concentrated to dryness under reduced pressure to give N-benzyloxycarbonyl-3-bromoethylamine as a colorless oil (15.020 g; 99% yield).LC-MS analysis: retention time t R = 0.95 min; [M + H]+: no ionization peak was observed.
References
[1] Journal of Medicinal Chemistry, 1981, vol. 24, # 4, p. 408 - 428
[2] Patent: US2011/105514, 2011, A1. Location in patent: Page/Page column 21
[3] Patent: WO2009/156951, 2009, A2. Location in patent: Page/Page column 47-48
[4] Chemical Communications, 2010, vol. 46, # 17, p. 2983 - 2985
[5] Journal of Organic Chemistry, 2000, vol. 65, # 26, p. 8979 - 8987