Purification of amido-carboxylic acids
US5393905A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1994 |
| Grant date | Feb 28, 1995 |
| Priority date | — |
| Expiry date | Apr 15, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C231/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to a four step process for purifying amido-carboxylic acids by liquid/liquid extraction from a reaction mixture containing an amido-carboxylic acid. The first step involves distilling impurities from a reaction mixture containing an amido-carboxylic acid to form a distillate residue. The second step involves mixing the distillate residue with a nonpolar hydrocarbon solvent wherein the mixture is maintained above the freezing point of the distillate residue. The third step involves allowing the hydrocarbon solvent and distillate residue to achieve phase separation of an organic phase containing the amido-carboxylic acid and an organic phase containing the nonpolar hydrocarbon solvent. The fourth step involves separating the organic phase containing the nonpolar hydrocarbon solvent from the organic phase containing the amido-carboxylic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.