反应详情

40 g (0.096 mol) of 2-[p-[(α,α,α-trifluoro-p-tolyl)oxy]phenoxy]-propionic acid [(methylthio)methyl]ester are dissolved in 120 ml of acetone/water (5:1) and treated slowly with 192 ml of a 30% solution of hydrogen peroxide. 96 ml of ammonium molybdate solution (35.2 g of ammonium molybdate in 96 ml of water) are added dropwise to the mixture which is cooled with an ice-bath. The mixture is stirred at room temperature for 2 hours. It is then extracted several times with ether, the ether extract is washed with sodium dithionite solution and the solution is again washed neutral with eight 100 ml portions of saturated sodium chloride solution and subsequently with five 100 ml portions of water. The mixture is treated with active carbon, filtered and evaporated. The residue is recrystallised from methylene chloride/n-hexane. There is obtained 2-[p-[(α,α,α-trifluoro-p-tolyl)oxy]phenoxy]-propionic acid [(methylsulphonyl)methyl]ester which melts at 87°-88° C.

1. temperatureis cooled with an ice-bath
2. extractionIt is then extracted several times with ether
3. extractionthe ether extract
4. washis washed with sodium dithionite solution
5. additionThe mixture is treated with active carbon
6. filtrationfiltered
7. customevaporated
8. customThe residue is recrystallised from methylene chloride/n-hexane