反应详情

6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran (9.637 g) (see Preparation 4) was dissolved in absolute ethanol (200 ml), then sodium tert-butoxide (11.029 g), 4-methoxybenzenethiol (4.9 ml) and tetrakis(triphenylphosphine)palladium(O) (0.454 g) were added and the mixture was heated under reflux under a nitrogen atmosphere for 48 hours. The solvent was removed under reduced pressure and the residue was dissolved in dichloromethane and washed with water. The organic layer was dried (anhydrous sodium sulphate), the solvent was removed under reduced pressure and the crude product was chromatographed on silica using 1:1, hexane: dichloromethane as the eluent to yield 6-(4-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (7.823 g) as a yellow oil.

1. temperaturethe mixture was heated
2. temperatureunder reflux under a nitrogen atmosphere for 48 hours
3. customThe solvent was removed under reduced pressure
4. dissolutionthe residue was dissolved in dichloromethane
5. washwashed with water
6. dry with materialThe organic layer was dried (anhydrous sodium sulphate)
7. customthe solvent was removed under reduced pressure
8. customthe crude product was chromatographed on silica using 1:1, hexane