Reaction #302895

Reaction equation

dimethyl disulfide

n-butyllithium

diisopropylamine

3-fluorobenzotrifluoride

→

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

Solvents

water

THF

Conditions

Workup

1. 1
   workup.STIRRINGthe reaction mixture was stirred at this temperature for 1 h
2. 2
   workup.WAITWithin about 3 h
3. 3
   Temperaturethe reaction mixture had warmed to room temperature (RT), and it
4. 4
   Temperaturewas then once more cooled to 0° C
5. 5
   Concentrationthe reaction mixture was concentrated to about ¼ of its volume
6. 6
   Otherdichloromethane, the phases were separated
7. 7
   Washthe 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
   Dryingdried over sodium sulfate
9. 9
   Filtrationfiltered
10. 10
    OtherThe solvent was removed

Procedure

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.

Source