METHOD FOR OBTAINING OCTAFLUOROTOLUENE Russian patent published in 2023 - IPC C07C25/13 C07C22/08 C07C17/20 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing octafluorotoluene by fluorodechlorination of pentachloro- or polyfluorochlorobenzotrifluorides of composition C₆F_nCl_5-nCF₃ (n=0÷4), or their mixtures with alkali metal fluorides, in the presence of a catalyst. The system of tetrakis(diethylamido)phosphonium salt – alkali metal tetrafluoroborate is used as a catalyst, the cation in alkali metal tetrafluoroborate is chosen similar to the alkali metal cation, the fluorodechlorination process is carried out at a 1.2-4.5-fold excess of alkali metal fluoride relative to stoichiometric value, whereas process is carried out when loading a combined catalyst, in particular tetrakis(diethylamido)phosphonium bromide in the amount of 2÷5 wt.% of the initial mixture of polyfluorochloroaromatic compounds and alkali metal tetrafluoroborate, in particular potassium tetrafluoroborate in the amount of 1.0÷2.5 wt.% of the original mixture of aromatic compounds, fluorodechlorination is carried out at a temperature of 100÷120°C.

EFFECT: reduced energy consumption and improved quality of the resulting technical product, as well as increased productivity of the process.

1 cl, 7 ex