反应详情

To a stirring solution of 3-Bromo-2-methyl-benzoic acid methyl ester (500 mg, 2.22 mmol) in carbon tetrachloride (6 mL) at 0° C., was added chromylchloride (0.36 mL, 4.45 mmol) and the reaction mixture was heated to reflux for 20 h. The reaction mixture was cooled to RT, added ice water and sat sodium bicarbonate solution at 0° C. Extracted with ethyl acetate (3×) the combined ethyl acetate layer was washed with brine and dried over anhydrous sodium sulphate and concentrated under reduced pressure. Purification by column chromatography (silica gel, 0-10% ethyl acetate in pet. ether) afforded 4-bromo-3H-isobenzofuran-1-one as a solid.

1. temperaturethe reaction mixture was heated
2. temperatureto reflux for 20 h
3. customat 0° C
4. extractionExtracted with ethyl acetate (3×) the combined ethyl acetate layer
5. washwas washed with brine
6. dry with materialdried over anhydrous sodium sulphate
7. concentrationconcentrated under reduced pressure
8. customPurification by column chromatography (silica gel, 0-10% ethyl acetate in pet. ether)