3-Isobutylaniline (14.9 g, 0.1 mol) was diluted in a 300 ml mixed solvent of tert-butyl methyl ether-water (1:1), followed by sequentially adding heptafluoroisopropyl iodide (29.6 g, 0.1 mol), tetrabutylammonium hydrogensulfate (3.4 g, 0.01 mol), sodium hydrogen carbonate (8.4 g, 0.1 mol) and sodium dithionite (17 g, 0.1 mol) and stirring overnight at room temperature. The reaction solution was diluted with hexane, followed by washing twice with a 3N HCl solution, and with aqueous sodium bicarbonate and a saturated brine. The solution was dried over magnesium sulfate and concentrated under reduced pressure, and then the residue was purified by using silica gel chromatography (hexane:ethyl acetate=6:1) to obtain 14.9 g of the desired compound.
