反应详情

To an ice-cooled mixture of 2-[3-bromo-4-(methyloxy)phenyl]ethanol (9.5 g, 41 mmol) and ethyl bis(ethyloxy)acetate (8.7 g, 48 mmol) in 60 mL of CH3NO2 was added TiCl4 (31.2 g, 169 mmol) over a period of 20 min. After stirring for 10 min, the ice bath was removed and the mixture was allowed to stir at room temperature over night. The mixture was poured onto ice/aqueous 1N HCl. Extracted by DCM and backwashed with 1N HCl and brine, dried over anhydrous sodium sulfate and concentrated. The residue was purified via column chromatography to give methyl 6-bromo-7-(methyloxy)-3,4-dihydro-1H-isochromene-1-carboxylate.

1. customthe ice bath was removed
2. stirringto stir at room temperature over night
3. additionThe mixture was poured onto ice/aqueous 1N HCl
4. extractionExtracted by DCM
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customThe residue was purified via column chromatography