反应详情

To a 0° C. solution of (5-chloro-4-methoxy-3-methyl benzofuran-2-yl)-methanol (0.29 g; 1.3 mmol) in dichloromethane (5 mL) was added neat phosphorus tribromide (0.18 mL; 0.52 g; 1.9 mmol; 1.5 eq) and pyridine (3 drops). The ice bath was removed and the reaction was allowed to warm to room temperature overnight. Additional phosphorus tribromide (0.09 mL; 0.26 g; 0.95 mmol; 0.75 eq) was added and stirring continued at room temperature. After two hours, the reaction was quenched with ice and extracted twice with ethyl acetate. The combined organic layers were washed with water and saturated sodium bicarbonate, followed by drying over magnesium sulfate, filtration and concentration in vacuo to give essentially pure 2-bromomethyl-5-chloro-4-methoxy-3-methyl benzofuran (0.37 g; 99%).

1. customThe ice bath was removed
2. customcontinued at room temperature
3. customthe reaction was quenched with ice
4. extractionextracted twice with ethyl acetate
5. washThe combined organic layers were washed with water and saturated sodium bicarbonate
6. dry with materialby drying over magnesium sulfate, filtration and concentration in vacuo