The general procedure for the synthesis of o-bromophenethylamine from o-bromobenzyl cyanide was as follows: 1 M borane-tetrahydrofuran complex (BH3-THF, 200 mL, 0.2 mol) was slowly added dropwise to a solution of 2-bromobenzyl cyanide (20.0 g, 0.1 mol) in tetrahydrofuran (THF, 100 mL) at 0 °C for 30 min. Subsequently, the reaction mixture was heated to reflux for 24 hours. Upon completion of the reaction, the reaction was quenched with methanol (MeOH, 50 mL) and 6 M hydrochloric acid (HCl, 50 mL) at 0 °C, and then the mixture was heated and refluxed again for 4 hours. The reaction solution was concentrated under reduced pressure and the residue was diluted with distilled water (H2O, 300 mL) and washed with ethyl acetate (EA, 75 mL × 2). The aqueous layer was neutralized with 15% sodium hydroxide (NaOH) solution and then extracted with ethyl acetate (EA, 75 mL × 2). The organic layers were combined, dried with anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to afford the target product o-bromophenethylamine (2a) as a yellow oil (17.4 g, 85.2% yield). High-resolution mass spectrometry (HRMS) calculated value C8H11NBr [M + H]+ 200.0069, measured value 200.0068. nuclear magnetic resonance hydrogen spectrum (1H NMR, 500 MHz, CDCl3) δ 7.58 (d, J = 8.0 Hz, 1H), 7.35-7.31 (m, 2H), 7.15 (t, J = 7.0 Hz, 1H). 2.79 (m, 4H), 1.18 (m, 2H). Nuclear magnetic resonance carbon spectrum (13C NMR, 125 MHz, DMSO-d6) δ 139.8,132.9,131.6,128.6,128.2,124.3,42.4,40.3.
