反应详情

To a solution of 4-trifluoromethoxyphenylacetic acid (5 g, 23 mmol) in carbon tetrachloride oxalyl chloride (25 mmol) and two drops of DMF were added at 0° C. After stirring the solution at room temperature for 1 h, NBS (25 mmol) and few drops of 48% HBr were added and the mixture was heated to reflux for 4 h. The solution was allowed to cool, MeOH (5 mL) was added and the mixture was stirred at room temperature for 1 h. After filtration through a pad of silica gel, the filtrate was evaporated in vacuo to give 7.2 g of the title compound as yellow foam, which was used in the subsequent step without further purification.

1. temperaturethe mixture was heated
2. temperatureto reflux for 4 h
3. temperatureto cool
4. stirringthe mixture was stirred at room temperature for 1 h
5. filtrationAfter filtration through a pad of silica gel
6. customthe filtrate was evaporated in vacuo