反应详情

Potassium carbonate (4.6 g, 33 mmol), potassium iodide (0.25 g, 1.5 mmol) and tert-butylbromoacetate (2.5 ml, 16.5 mmol) were added to a solution of 4-hydroxy-3-methyl-benzoic acid methyl ester from Example E29 (2.5 g, 15 mmol) in acetone (150 ml) and the mixture was heated at reflux for 20 h. The solid was filtered off and the filtrate concentrated in vacuo. The residue was dissolved in EtOAc, washed with 1N KHSO4, water then brine, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; 15% EtOAc:85% hexane) to yield the title compound (3.8 g, 90%).

1. temperaturethe mixture was heated
2. temperatureat reflux for 20 h
3. filtrationThe solid was filtered off
4. concentrationthe filtrate concentrated in vacuo
5. dissolutionThe residue was dissolved in EtOAc
6. washwashed with 1N KHSO4, water
7. dry with materialbrine, dried
8. concentrationconcentrated in vacuo
9. customThe residue was purified by flash chromatography on silica gel (eluant; 15% EtOAc:85% hexane)