反应详情

6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran (9.6 g) (see Preparation 4) was dissolved in absolute ethanol (200 ml), then sodium tert-butoxide (11.0 g), 2-methoxybenzenethiol (5.3 g) and tetrakis(triphenylphosphine)palladium(0) (0.45 g) were added and the mixture heated under reflux under a nitrogen atmosphere for 24 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 first on silica using 1:1 hexane:dichloromethane as the eluent and then on silica using 24:1 hexane:ethyl acetate as the eluent to yield 6-(2-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (8.12 g) as an oil.

1. temperaturethe mixture heated
2. temperatureunder reflux under a nitrogen atmosphere for 24 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 first on silica using 1:1 hexane