反应详情

To a solution of 4-chloro-2-ethyl-1-methoxybenzene (Preparation 5, 7.0 g, 41.0 mmol) in dichloromethane (20 mL) at 0° C. was added a 1M solution of boron tribromide in dichloromethane (20.5 mL, 20.5 mmol). After 2 hours, further boron tribromide solution (20 mL, 20.0 mmol) was added. After a further 2 hours, methanol was added and the reaction mixture concentrated in vacuo. The residue was purified by silica gel column chromatography (5%-40% ethyl acetate in heptane) to afford the title compound (3.7 g, 58%).

1. waitAfter a further 2 hours
2. concentrationthe reaction mixture concentrated in vacuo
3. customThe residue was purified by silica gel column chromatography (5%-40% ethyl acetate in heptane)