Method of preparing trifluoromethanesulfonic acid anhydride
US5004829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1990 |
| Grant date | Apr 2, 1991 |
| Priority date | — |
| Expiry date | Apr 9, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/90
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
(CF.sub.3 SO.sub.2).sub.2 O is formed by reaction of CF.sub.3 SO.sub.3 H with P.sub.2 O.sub.5 and taken out of the reaction system by distillation, but the residue of the distillation contains a considerable amount of unreacted CF.sub.3 SO.sub.3 H. From the residue unreacted by adding water or a phosphoric acid solution, preferably the latter, to the residue to obtain a fluidic mixture containing an adequate amount of water and subjecting the mixture to distillation, preferably under reduced pressure at temperatures ranging from 180.degree. to 280.degree. C. It is possible to form additional CF.sub.3 SO.sub.3 H during the recovery process by adding a metal salt of CF.sub.3 SO.sub.3 H to the aformentioned mixture since the metal salt is decomposed by phosphoric acid contained in the mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.