Isopropanol → 4-Bromo-3-chloro-3,4,4-trifluorobutanoic acid

A solution of 4-bromo-3-chloro-3,4,4-trifluorobutanol (IX) (2.41 g, 10 mmol) in acetone (35 mL) was treated with Jones reagent (7.5 mL) in 10 min with stirring and cooling (ice-water bath). The mixture was then stirred at room temperature for 30 min and 0.5 mL of i-propanol was then added. The precipitated salts were removed by filtration, washed with acetone. The residue obtained after concentration of the flitrate was dissolved in methylene chloride (100 mL), washed with 1N HCl (50 mL), brine, and dried over anhydrous magnesinm sulfate. Evaporation of the solvent gave 2.17 g (85%) of 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) as a clear oil.