Process for recycling amido-carboxylic acid esters into amino-carboxylic acids
US6497644B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2001 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Jul 6, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
According to the invention, waste materials containing amido-carboxylic acid esters, which are generated during the preparation of phenyl ester salts, can be converted into amido-carboxylic acids. The recovered amido-carboxylic acid is then useful in the preparation of additional phenyl ester salt by the original preparation process or other processes known in the art. The process of the invention combines a waste material containing amido-carboxylic acid esters with an aqueous solution of a strong acid having a pH less than about 1 to form a mixture. The process heats the mixture to a temperature of at least 90° C. and maintains the mixture at that temperature for a time sufficient to hydrolyze the amido-carboxylic acid esters to amido-carboxylic acids. Sufficient base is the added to adjust the pH of the mixture to greater than about 2. The mixture is then maintained at a temperature of at least 80° C. for a time sufficient to allow phase separation of the aqueous and organic phases within the mixture. The organic phase and the aqueous phase are then separated and the amido-carboxylic acids recovered from the organic phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.