Synthesis
General procedure for the synthesis of 3-bromo-4-chlorobenzyl alcohol from 3-bromo-4-chlorobenzoic acid:
A. To a mixture of 3-bromo-4-chlorobenzoic acid (10.0 g, 42.5 mmol) in THF (50 mL) was slowly added 1.0 M borane-THF solution (55.3 mL, 55.3 mmol) under nitrogen protection and at 0 °C. The reaction mixture was stirred overnight at room temperature and then carefully poured into a mixture of NaHCO3/H2O/ice and extracted with EtOAc. The organic layer was washed with saturated aqueous NaCl, dried over MgSO4, filtered and concentrated under reduced pressure to afford the target product 3-bromo-4-chlorobenzyl alcohol (9.4 g, 100%) as a clear, colorless oil.1H NMR (300 MHz, CDCl3) δ 7.61 (s, 1H), 7.41 (d, J = 5.1 Hz, 1H), 7.21 (d, J = 5.1 Hz, 1H), 4.63 (s, 2H), 2.12 (br s, 1H).
References
[1] Patent: WO2011/79102, 2011, A1. Location in patent: Page/Page column 132
[2] Synlett, 2014, vol. 25, # 1, p. 123 - 127
[3] Patent: WO2013/142396, 2013, A1. Location in patent: Page/Page column 55
[4] Patent: US2006/154915, 2006, A1. Location in patent: Page/Page column 29
[5] Patent: WO2003/99776, 2003, A1. Location in patent: Page 63
