abstract |
The present invention combusts tetrachlorophthalic anhydride to obtain 3,3,4,5,6,7, -hexachloro-1- [3H] -isobenzofuranone, and then fluorinates it to 3,4,5 , 6-tetrafluorophthaloyldifluoride and / or 3,3,4,5,6,7, -hexafluoro-1- [3H] -isobenzofuranone to give, tetrafluorophthaloyldifluoride and / Or a method for producing tetrafluorophthalic anhydride comprising reacting hexafluoro-1- [3H] -isobenzofuranone with an inorganic base or an organic acid to obtain tetrafluorophthalic anhydride. |