Process for the preparation of fluoromethyl 2,2,2-trifluoro-1-(trifluoromethyl) ethyl ether
US8044247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2006 |
| Grant date | Oct 25, 2011 |
| Priority date | — |
| Expiry date | Apr 2, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C41/44
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention refers to a process for the preparation of fluoromethyl 2,2,2-trifluoro-1-(trifluoromethyl)ethyl ether (sevoflurane) which includes a step that consists of reacting hexafluoroisopropanol with a formaldehyde equivalent selected among paraformaldehyde or 1,3,5-trioxane, a chlorinating agent selected from the group consisting of oxalyl chloride, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, sulfuryl chloride and thionyl chloride, and a strong acid selected from the group consisting of concentrated or fuming sulfuric acid resulting in the formation of the intermediate sevochlorane which is converted to sevoflurane in a second step which consists of reacting sevochlorane with an alkali metal fluoride, or a linear or branched chain tetra-alkyl quarternary ammonium fluoride in the presence of a sub-stoichiometric quantity of an alkali metal iodide, or a linear or branched alkyl chain tetra-alkyl quarternary ammonium iodide, preferably in a solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.