To a solution of 2-methyl-3-methoxyaniline (5.0 g, 36.5 mmol) in p-xylene (80 mL) was cooled to 0 °C, and a dichloromethane solution (36.5 mL) of 1 M BCl3 was slowly added. The reaction mixture was stirred at 0 °C for 30 min under nitrogen protection. Subsequently, acetonitrile (2.6 mL, 54.7 mmol) was added and stirring was continued at 0 °C for 30 min. In another reaction flask, AlCl3 (4.87 g, 36.5 mmol) was suspended in anhydrous dichloromethane (50 mL), cooled to 0 °C, and the aforementioned p-xylene solution was added dropwise through the addition funnel under nitrogen protection. After addition, the dichloromethane was removed under vacuum after stirring at 0°C for 45 minutes. The remaining p-xylene solution was heated to 70°C and maintained for 18 hours, followed by cooling to room temperature. Water (80 mL) was added and again heated to 70°C maintained for 1 hour and cooled to room temperature. The reaction mixture was diluted with ethyl acetate and the aqueous layer was separated. The organic layer was washed sequentially with equal volumes of water and saturated saline, dried over anhydrous MgSO4 and concentrated under reduced pressure. 1H), 7.03 (br.s., 2H), 7.65 (d, J = 9.04 Hz, 1H). LC-MS (ESI): m/z 180.10 (M + H)+.
