Process for the preparation of tetrafluorophthalic acid and/or tetrafluorophthalic anhydride
US5384413A · kind A · utility
3Cited by
3References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1993 |
| Grant date | Jan 24, 1995 |
| Priority date | — |
| Expiry date | Jul 12, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D209/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a process for the preparation of tetrafluorophthalic acid and/or tetrafluorophthalic anhydride by reacting a compound of the formula ##STR1## in which X is a radical ##STR2## which is optionally mono- or polysubstituted on the aromatic nucleus by fluorine and/or chlorine and/or alkyl groups having 1 to 4 carbon atoms, or is a radical ##STR3## in which R.sub.1, R.sub.2 and R.sub.3 are as defined, with water, and subsequently removing the water still present by azeotropic distillation or extracting the tetrafluorophthalic acid and/or its anhydride with a water-insoluble solvent or solvent mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.