1000994-95-5

Example 63A Synthesis of 1-bromo-4-(1,1-difluoroethyl)benzene: Under argon protection, 3.0 g (15.07 mmol) of 1-(4-bromophenyl)ethanone was dissolved in 30 mL of dichloromethane, followed by the slow addition of 15.9 mL (120.57 mmol) of [ethyl (trifluoro-lambda4-thioalkyl)amino]ethane (DAST). The reaction mixture was slowly warmed to 50 °C and stirred at this temperature overnight. Upon completion of the reaction, the reaction mixture was slowly poured into ice water. The organic phase was separated and the aqueous phase was extracted three times with dichloromethane. The organic phases were combined and dried with magnesium sulfate. After filtration, the solvent was removed by concentration under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: petroleum ether/dichloromethane=4:1) to afford 2.56 g (11.58 mmol, 77% yield) of 1-bromo-4-(1,1-difluoroethyl)benzene as a pale yellow liquid. gC-MS (Method 1): rt = 2.84 min; m/z = 220/222 (M)+.

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