Reaction #1269821

Reaction equation

triethylamine

pivaloyl chloride

2-bromo-2,2-difluoroethanol

diisopropyl ether

hydrochloric acid

→

2-bromo-2,2-difluoroethyl pivalate

Yield 82.0%

Solvents

water

Conditions

Workup

1. 1
   Temperaturewhile cooling the flask in an ice bath
2. 2
   workup.STIRRINGAfter the dropping, the solution was kept stirred for 1 hour at room temperature
3. 3
   OtherThe thus-obtained solution was separated into an organic phase
4. 4
   ExtractionThe aqueous phase was extracted with 500 ml of diisopropyl ether
5. 5
   WashThe resulting organic phase was washed with 500 ml of saturated sodium chloride solution
6. 6
   Dryingdried with anhydrous sodium sulfate
7. 7
   Othersubjected to solvent evaporation

Procedure

In a glass flask with a thermometer, a condenser and a dropping funnel, 271 g (2.24 mol) of pivaloyl chloride, 360 g (2.23 mol) of 2-bromo-2,2-difluoroethanol and 1.5 L of diisopropyl ether were placed. The resulting solution was stirred, followed by dropping 318 g (3.14 mol) of triethylamine to the stirred solution while cooling the flask in an ice bath. After the dropping, the solution was kept stirred for 1 hour at room temperature. The completion of the reaction was then confirmed by gas chromatography of the solution. The reaction solution was admixed with and totally dissolved in 300 ml of water. After that, 500 ml of 2N hydrochloric acid was added to the solution. The thus-obtained solution was separated into an organic phase and an aqueous phase. The aqueous phase was extracted with 500 ml of diisopropyl ether. The extract was combined with the organic phase. The resulting organic phase was washed with 500 ml of saturated sodium chloride solution, dried with anhydrous sodium sulfate, and then, subjected to solvent evaporation. With this, 85 g of 2-bromo-2,2-difluoroethyl pivalate was obtained as a light yellow liquid (yield: 82%, purity: 93%).

Source