Reaktion #302895

Reaktionsgleichung

dimethyl disulfide

n-butyllithium

diisopropylamine

3-fluorobenzotrifluoride

→

1-fluoro-2-methylthio-3-(trifluoromethyl)benzene

Lösungsmittel

water

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction mixture was stirred at this temperature for 1 h
2. 2
   workup.WAITWithin about 3 h
3. 3
   Temperaturthe reaction mixture had warmed to room temperature (RT), and it
4. 4
   Temperaturwas then once more cooled to 0° C
5. 5
   Einengenthe reaction mixture was concentrated to about ¼ of its volume
6. 6
   Sonstigedichloromethane, the phases were separated
7. 7
   Waschenthe organic phase was washed successively with water, 10 percent strength hydrochloric acid, water, saturated aqueous NaHCO3 solution, water and saturated aqueous NaCl solution
8. 8
   Trocknendried over sodium sulfate
9. 9
   Filtrationfiltered
10. 10
    SonstigeThe solvent was removed

Vorschrift

Under an atmosphere of inert gas, 32.8 ml (1.6 M in hexane, 52.5 mmol) of n-butyllithium were added dropwise to a solution, cooled to 0° C., of 7.77 ml (55 mmol) of diisopropylamine in 100 ml of anhydrous THF, and after 10 minutes of stirring the solution was cooled to −78° C. 8.21 g (50 mmol) of 3-fluorobenzotrifluoride were added at this temperature, and the reaction mixture was stirred at this temperature for 1 h. 4.21 ml (55 mmol) of dimethyl disulfide were then added dropwise. Within about 3 h, the reaction mixture had warmed to room temperature (RT), and it was then once more cooled to 0° C. At this temperature, 10 ml of water were added dropwise, and the reaction mixture was concentrated to about ¼ of its volume. The residue was taken up in water and dichloromethane, the phases were separated and the organic phase was washed successively with water, 10 percent strength hydrochloric acid, water, saturated aqueous NaHCO3 solution, water and saturated aqueous NaCl solution and dried over sodium sulfate and filtered. The solvent was removed and the residue was rectified under reduced pressure. This gave 8 g of 1-fluoro-2-methylthio-3-(trifluoromethyl)benzene of a boiling point of 68° C. at 6 mm Hg.

Quelle