反应详情

3-Fluoro-4-methylbenzoic acid methyl ester from Example E3.1 (4.5 g, 26.6 mmol) was dissolved in carbon tetra-chloride (150 ml). AIBN (457 mg, 2.7 mmol) and N-bromosuccinimide (5.2 g, 29.3 mmol) were added and the mixture was heated at reflux for 18 h. The mixture was allowed to cool and further portions of AIBN (457 mg, 2.7 mmol) and N-bromosuccinimide (5.2 g, 29.3 mmol) were added. The mixture was heated at reflux for 56 h. The mixture was allowed to cool and evaporated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; 10% EtOAc:90% pet ether) to yield the title compound (2.7 g, 41%).

1. temperaturethe mixture was heated
2. temperatureat reflux for 18 h
3. temperatureto cool
4. temperatureThe mixture was heated
5. temperatureat reflux for 56 h
6. temperatureto cool
7. customevaporated in vacuo
8. customThe residue was purified by flash chromatography on silica gel (eluant; 10% EtOAc:90% pet ether)