反应详情

3-(2-Bromo-3-trifluoromethyl-phenyl)-propionic acid (3.25 g) in trifluoromethane-sulfonic acid (30 ml) is stirred at 75° C. for 2.5 h. After cooling to room temperature, the mixture is poured into water and the resulting mixture is extracted with ethyl acetate. The combined organic extract is washed with aqueous NaHCO3 solution, dried (Na2SO4), and concentrated. The residue is chromatographed on silica gel (cyclohexane/ethyl acetate 90:10→80:20) to afford the title compound. LC (method 5): tR=0.90 min.

1. extractionthe resulting mixture is extracted with ethyl acetate
2. extractionThe combined organic extract
3. washis washed with aqueous NaHCO3 solution
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated
6. customThe residue is chromatographed on silica gel (cyclohexane/ethyl acetate 90:10→80:20)