反应详情

To a solution of 3-chloro-5-trifluoromethoxyphenylactic acid (5.2 g, 20.4 mmol; see step (iii) above) in EtOH (600 mL) was added sulfuric acid (several drops). The solution was refluxed for 18 h, cooled to room temperature, neutralized with solid NaHCO3 and the EtOH removed in vacuo. The residue was diluted with EtOAc then washed with H2O (1×), aqueous NaHCO3 (1×) and brine (1×). The organics were dried (Na2SO4), filtered and concentrated in vacuo to afford the sub-title compound (5.5 g, 96%) as an oil which was used in the next step without further purification.

1. temperatureThe solution was refluxed for 18 h
2. customthe EtOH removed in vacuo
3. additionThe residue was diluted with EtOAc
4. washthen washed with H2O (1×), aqueous NaHCO3 (1×) and brine (1×)
5. dry with materialThe organics were dried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated in vacuo