Catalysis in halogen exchange reactions
US5965781A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1997 |
| Grant date | Oct 12, 1999 |
| Priority date | — |
| Expiry date | Nov 21, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/025
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Impure tetra(dihydrocarbylamino)phosphonium halide is contacted with a liquid cyclic ether to dissolve the phosphonium halide and leave at least a portion of the impurities comprising at least quaternary ammonium halide or an amidophosphoxide remaining in the solid state. The solids and the liquid phase are separated from each other, an anhydrous non-solvent for the tetra(dihydrocarbylamino)phosphonium halide is mixed with the separated liquid phase to precipitate the tetra(dihydrocarbylamino)phosphonium halide, which is then separated from the liquid phase. The so-treated tetra(dihydrocarbylamino)phosphonium halide is more efficient as a catalyst for halogen exchange reactions than the original untreated tetra(dihydrocarbylamino)phosphonium halide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.