To a stirred solution of 2,6-diisopropylaniline (14 g, 78.97 mmol, 1.00 eq.) in N,N-dimethylformamide (200 mL) was slowly added dropwise a solution of N-bromosuccinimide (NBS, 14 g, 78.65 mmol, 1.00 eq.) in N,N-dimethylformamide (100 mL) at 0 °C, the dropwise time was controlled to 60 min. The reaction mixture was continued to be stirred at 0 °C for 1 hour. Subsequently, water (900 mL) was added to the reaction system to quench the reaction. The reaction mixture was extracted with ethyl acetate (300 mL). The organic layers were combined and washed sequentially with saturated ammonium chloride solution (3 x 100 mL) and water (1 x 100 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford 4-bromo-2,6-diisopropylaniline 20.05 g in 99% yield as a red oil.1H NMR (400 MHz, DMSO-d6): δ 6.95 (s, 2H), 4.77 (s, 2H), 5.47-5.39 (m, 1H), 3.04-2.98 (m, 1H) , 1.13 (d, J = 6.8 Hz, 12H) ppm.
