反应详情

5 g (27.5 mmol) of 3,4-Dihydroxy-benzoic acid ethyl ester was dissolved in 110 ml of DMF and treated at 0° C. with 3.8 g (27.5 mmol) of potassium carbonate and 3.38 g (27.5 mmol) of isopropyl bromide. The solution was stirred for 16 h at RT, then a further 1.014 g (8.3 mmol) of isopropyl bromide was added. The reaction solution was heated at 50° C. for 3 h. The solvent was removed under reduced pressure, the residue was taken-up in ethyl acetate and the solution was washed three times with water and twice with saturated aqueous sodium chloride. The organic phase was dried with magnesium sulphate, filtered and the solvent was removed under reduced pressure. The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (5/1).

1. temperatureThe reaction solution was heated at 50° C. for 3 h
2. customThe solvent was removed under reduced pressure
3. washthe solution was washed three times with water
4. dry with materialThe organic phase was dried with magnesium sulphate
5. filtrationfiltered
6. customthe solvent was removed under reduced pressure
7. customThe residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (5/1)