反应详情

Methyl pentafluoroethyl ketone (3.9 g, 0.02407 mole) (JACS, 78, 2268-70 [1956]) was stirred in concentrated sulphuric acid (10 ml) at room temperature under a dry-ice condenser. Bromine (1.92 g; 0.012035 mole) was added slowly over two hours with vigorous stirring. The mixture was then stirred for one hour at room temperature and then at 50° C. for one hour. The resulting amber solution was distilled at atmospheric pressure, yielding one main fraction of 4.41 g (76%), boiling at 94-97° C. The mass spectrum confirmed the structure, showing parent ions at 240 and 242 m/e corresponding to C4H2BrF5O (2 isotopes of Br).

1. waitat 50° C. for one hour
2. distillationThe resulting amber solution was distilled at atmospheric pressure
3. customyielding one main fraction of 4.41 g (76%), boiling at 94-97° C