Sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate

13755-29-8

328-70-1

79060-88-1

The general procedure for the synthesis of sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate from sodium fluoborate and 3,5-bis(trifluoromethyl)bromobenzene was as follows: first, a three-necked round-bottomed flask fitted with a reflux condenser was evacuated, flame-dried and replaced with argon. Subsequently, 1.01 g (41.7 mmol) of magnesium shavings, 0.72 g (6.4 mmol, 1 equiv.) of sodium fluoborate (NaBF4) and 150 mL of anhydrous ether were added to the flask. To initiate the reaction, 1.07 g (0.49 mL, 5.7 mmol, 0.9 eq.) of dibromoethane was added, and after heating the flask slightly for a few minutes, 1.71 g (6.25 mL, 36 mmol) of 3,5-bis(trifluoromethyl)bromobenzene was slowly added dropwise. After 30 minutes of reaction, the reaction mixture was diluted with 50 mL of ether. After the exothermic reaction slowed down, the reaction mixture was continued to be heated for 30 minutes. Subsequently, the reaction solution was stirred at room temperature overnight. Upon completion of the reaction, 16 g of sodium carbonate (Na2CO3) was added to 200 mL of distilled water to quench the reaction, stirred for 30 minutes and then filtered. The aqueous phase was extracted three times with 50 mL of ether, the organic phases were combined and dried with anhydrous sodium sulfate and activated carbon, and filtered. The solvent was removed under reduced pressure and the residual crude product was dissolved in 200 mL of toluene and the water was removed by azeotropic boiling through a Dean-Stark water separator. The solvent was again removed under reduced pressure, the product was filtered, washed with anhydrous toluene and dried under vacuum to give 4.65 g (5.3 mmol, 82% yield) of a colorless solid product with melting point decomposition >290 °C. The product was subjected to 1H-NMR (300 MHz, DMSO-d6), 13C-NMR (75.5 MHz, DMSO-d6), 19F-NMR (283 MHz, DMSO-d6) and elemental analysis to confirm the structure. Elemental analysis (C32H12BF24Na-1.8H2O) Calculated value: C=41.61, H=1.70; measured value: C=41.57, H=1.66.