| 摘要 |
A process for preparing 1,1-dihalo-1,2,2,2-tetrafluoroethanes by isomerization of 1,2-dihalotetrafluoroethanes at their reflux temperature, by using, as a catalyst, the reaction product prepared "in situ" from an anhydrous aluminum halide with at least equimolecular amounts of the isomer, 1,1-dihalo-1,2,2,2-tetrafluoroethane in a medium consisting of 1,2-dihalotetrafluoroethane. The products find application as intermediates for pyrethroid insecticides. |
