反应详情

To a stirred solution of Ethyl 2-(3-methoxy-4-methylphenyl)acetate (Step B, 4.12 g, 19.8 mmol) in methylene chloride (30 ml) was added BBr3 (1M in CH2Cl2, 25 ml) at −78° C. under argon, the cold bath was substituted by ice bath after 30 minutes and the reaction mixture was stirred at the same temperature for 2 hours and then 30 minutes at room temperature. The reaction mixture was quenched by addition of ice and worked up by washing with water and brine. The organic layer was dried over Na2SO4, filtered, concentrated, and purified by flash chromatography on a silica gel column (hexane:ethyl acetate, 2:1) to give the title compound.

1. custom30 minutes
2. customat room temperature
3. customThe reaction mixture was quenched by addition of ice
4. washby washing with water and brine
5. dry with materialThe organic layer was dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. custompurified by flash chromatography on a silica gel column (hexane:ethyl acetate, 2:1)