Isolation of phenyl ester salts from mixtures comprising sulfolane
US6498124B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 2001 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Jun 1, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C303/44
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for isolating a phenyl ester salt from a mixture comprising sulfolane (tetrahydrothiophene-1,1-dioxide). The invention includes adjusting the temperature of a mixture comprising a phenyl ester salt and sulfolane to a temperature of about 100-150° C. This step leads to the formation of a mixture comprising a solid phenyl ester salt and sulfolane. Next, the solid phenyl ester salt is separated, while maintaining the temperature of the mixture at about 100-150° C. The invention also relates to a process that includes adding a sufficient amount of a solvent to a mixture comprising a phenyl ester salt and sulfolane to decrease the viscosity or the density of the mixture. The solvent added has a density less than about 1.20 g/cm3 at 100° C. or a viscosity of less than about 2.56 centipoise at 100° C. The embodiments of the invention may be used alone or in combination. This invention may be used for the isolation of a variety of phenyl ester salts, including but not limited to sodium 4-sulfophenyl-6-[(1-oxynonyl)amino]hexanoate, sodium 4-(nonanoyloxy) benzenesulfonate, and sodium benzoyloxybenzenesulphonate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.