Production of D,L-aspartic acid
US5872285A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1996 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | Jun 10, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C227/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention is directed to a method for the production of D,L-aspartic acid. The method comprises reacting an unsaturated dicarboxylic acid or anhydride, such as, maleic acid, fumaric acid, maleic anhydride, or mixtures thereof, with excess aqueous ammonia at an elevated temperature and pressure for a time sufficient to produce diammonium D,L-aspartate. The produced diammonium D,L-aspartate is then neutralized to D,L-aspartic acid. Excess unreacted ammonia and various by-products may be recycled and re-used in the method, thereby minimizing waste and reducing cost. The produced D,L-aspartic acid may be subsequently used to make polyaspartic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.