Synthesis
General procedure for the synthesis of (3-bromo-5-fluorophenyl)methanol from 3-bromo-5-fluorobenzoic acid: 3-bromo-5-fluorobenzoic acid (1.0 g, 4.52 mmol) was suspended in tetrahydrofuran (8 mL) and the mixture was cooled to 0°C. Borane tetrahydrofuran complex (1 M in tetrahydrofuran, 9 mL, 9.0 mmol) was added slowly and dropwise over 15 min. The reaction mixture was gradually warmed to room temperature and stirred overnight. Upon completion of the reaction, the mixture was cooled again to 0 °C and the reaction was quenched by careful addition of excess methanol. Subsequently, the reaction mixture was diluted with ethyl acetate and washed sequentially with 1 N sodium hydroxide solution (2×) and saturated brine (2×). The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 0.88 g (95% yield) of the white solid product (3-bromo-5-fluorophenyl)methanol. The structure of the product was confirmed by 1H-NMR (CDCl3, 500 MHz): δ 7.29 (s, 1H), 7.16 (d, J = 7.9 Hz, 1H), 7.03 (d, J = 9.2 Hz, 1H), 4.66 (s, 2H).
References
[1] Patent: US2007/249607, 2007, A1. Location in patent: Page/Page column 81
[2] Patent: CN104447730, 2017, B. Location in patent: Paragraph 0146-0147
[3] Patent: WO2016/54728, 2016, A1. Location in patent: Paragraph 00127
[4] Patent: WO2016/74068, 2016, A1. Location in patent: Paragraph 00121
[5] Patent: WO2006/79791, 2006, A1. Location in patent: Page/Page column 44
