Synthesis
Tert-Butyl 4-bromobenzylcarbamate is prepared by the reaction of di-tert-butyl dicarbonate and 4-bromobenzylamine hydrochloride. The specific synthesis steps are as follows:
To a stirred suspension of 4-bromo-benzylamine hydrochloride (968mg, 4.35mmol) and triethylamine (0.666ml, 4.79mmol) in chloroform (15ml) was added di-tert-butyldicarbonate (949mg, 4.35mmol). The resulting solution was stirred at ambient temperature for 2h and then diluted with DCM (40ml). The organic solution was washed sequentially with 10% aqueous citric acid (40ml) and brine (40ml). The organic phase was dried over anhydrous magnesium sulfate and the filtrate evaporated at reduced pressure to afford Tert-Butyl 4-bromobenzylcarbamate (1.23g, 99%). 1H NMR 7.48-7.43 (2H, m), 7.18 (2H, d, 8.4), 4.84 (1H, br s), 4.27 (2H, d, 5.7), 1.46 (9H, s).
References
[1] Patent: EP1056733, 2004, B1. Location in patent: Page 26
[2] Patent: WO2007/28083, 2007, A2. Location in patent: Page/Page column 84
[3] Patent: CN105622638, 2016, A. Location in patent: Paragraph 0312
[4] Tetrahedron, 2001, vol. 57, # 23, p. 4945 - 4954
[5] Chemistry - A European Journal, 2017, vol. 23, # 12, p. 2877 - 2883
