To a solution of 5.0 g of o-carbethoxyphenyl-n-propyl-n-octadecylsulfonium tetrafluoroborate in 20 ml. of ethanol is added 20.0 g of potassium tosylate dissolved in a mixture of 200 ml. ethanol and 10 ml. water. The reaction mixture is maintained at 80°-90° while being stirred vigorously for 2 hours. The reaction mixture is then cooled and filtered, and the filtrate then evaporated under vacuum to dryness to obtain a residue. The residue is taken up in methylene chloride; the organic phase washed several times with water, dried over sodium sulphate, filtered and evaporated under vacuum to dryness. The residue is chromatographed over silica gel three times using methylene chloride and increasing amounts of methanol to obtain the title product m.p. 65°-67°.
