反应详情

100 g (0.03 mol) of 2-[p-[(α,α,α-trifluoro-p-tolyl)oxy]phenoxy]-propionic acid and 252 g (3.0 mol) of sodium bicarbonate are suspended in 2.5 liters of dimethyl sulphoxide and thereafter treated slowly with 336.5 ml (3.0 mol) of tert.butyl bromide. The mixture is stirred at room temperature overnight. The mixture, including the separated thick precipitate, is subsequently taken up in 5 liters of ethyl acetate. The ethyl acetate solution is washed twice with 1 liter of water, dried over sodium sulphate and evaporated. The residue is chromatographed on a 10-fold amount of silica gel with hexane/ethyl acetate (7:1) and the eluate is evaporated. There is obtained 2-[p-[(α,α,α-trifluoro-p-tolyl)oxy]phenoxy]-propionic acid [(methylthio)methyl]ester in the form of an oil.

1. washThe ethyl acetate solution is washed twice with 1 liter of water
2. dry with materialdried over sodium sulphate
3. customevaporated
4. customThe residue is chromatographed on a 10-fold amount of silica gel with hexane/ethyl acetate (7:1)
5. customthe eluate is evaporated