Hydrogen Bromide → 2-(alpha,alpha,beta,beta-Tetrafluorophenethyl)benzyl bromide

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Reaction Steps

A suspension of 3.3 g. (0.0116 mole) of 2-(α,α,β,β-tetrafluorophenethyl)benzyl alcohol in 15 ml. of 48% hydrobromic acid is stirred and heated on the steam bath for 3 hours. The product crystallizes from the cooled mixture and is collected and dissolved in benzene. Evaporation of the washed and dried benzene extract under reduced pressure and sublimation of the residual solid at 60°C. and 0.05 mm. yields white crystals, m.p. 70°-77°C. A sample for analysis from a previous preparation was purified by column chromatography on silica, eluting the product with benzene-carbon tetrachloride (2:1). The fractions that showed one spot of rf 0.85 on a fluorescent silica, thin layer plate developed with benzene were combined and the solvent evaporated under reduced pressure. The residual solid, m.p. 78°-82°C., was sublimed at 60°C. and 0.05 mm. to yield product, m.p. 80.5°-82°C.

Provenance & Evidence