3.3- difluoro-2-phenylpropan

Difluoro-l-phenylpropane (35) on elimination of hydrogen fluoride gives 1-fluoro-l-phenyl-prop-l-ene.41 42... 

Phcnylprop-l-ync (2.5 mL, 20 mmol) was dissolved in a mixture of CFClj (5 mL) and EtjO (5mL). NaF (2.0 g. 48 mmol) was added and the entire mixture was thoroughly degassed. OFj (20 mmol) was passed into the reactor and workup began at 50% OF, consumption. This required 70 min at - 78" C. The excess OFj was removed and the sodium fluoride was separated by filtration. The solvent was fractionated away and the pale yellow, unstable oil was analyzed by (iC. The major product (81 % yield) was assigned the structure 2.2-difluoro-l-phenylpropan-l-one and was accompanied by benzoyl fluoride (18%). 

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