反应详情

1,3-Dibromopropane (2.2 g, 11.0 mmol), potassium carbon-ate (1.86 g, 13.6 mmol) and potassium iodide (90 mg, 0.5 mmol) were added to 3-fluoro-4-hydroxy-benzoic acid ethyl ester from Example E27 (11.0 g, 5.4 mmol) in acetone (25 ml) and the mixture was heated at reflux for 20 h. The solid was filtered off and washed with EtOAc. The filtrate was concentrated in vacuo and azeotroped with toluene. The residue was purified by flash chromatography on silica gel (eluant; 20% EtOAc:80% hexane) to yield the title compound (1.18 g, 71%).

1. temperaturethe mixture was heated
2. temperatureat reflux for 20 h
3. filtrationThe solid was filtered off
4. washwashed with EtOAc
5. concentrationThe filtrate was concentrated in vacuo
6. customazeotroped with toluene
7. customThe residue was purified by flash chromatography on silica gel (eluant; 20% EtOAc:80% hexane)