Synthesis
General procedure for the synthesis of (4-bromo-2-fluorophenyl)methanamine from 4-bromo-2-fluorobenzonitrile: 4-bromo-2-fluorobenzonitrile (5.00 mmol) was dissolved in tetrahydrofuran (THF, 30 mL) and the solution was cooled to 0°C. A solution of borane tetrahydrofuran complex (1 M solution of THF, 15.0 mL) was added slowly and dropwise with stirring. The reaction mixture was continued to be stirred at 0 °C for 20 min, followed by warming to room temperature and stirring for 16 hours. Upon completion of the reaction, methanol (MeOH, 30 mL) was added slowly and dropwise to quench the reaction, followed by concentration of the solution under reduced pressure. The residue was extracted by partitioning with 1 M aqueous sodium hydroxide (NaOH) and ethyl acetate (EtOAc). The organic layer was separated and post-processed to give (4-bromo-2-fluorophenyl)methylamine (5.00 mmol) as a yellow oil.1H NMR (400 MHz, CDCl3) data: δ 7.42-7.27 (m, 1H), 7.25-7.16 (m, 2H), 3.65 (t, J = 6.6 Hz, 2H).
References
[1] Journal of Organic Chemistry, 2008, vol. 73, # 5, p. 1898 - 1905
[2] Journal of Organic Chemistry, 2009, vol. 74, # 5, p. 1964 - 1970
[3] Patent: WO2017/103611, 2017, A1. Location in patent: Paragraph 00336
[4] Patent: WO2018/75871, 2018, A1. Location in patent: Page/Page column 62
