Process for recovery of pyridine-2,3-dicarboxylic acid
US6133450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1999 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Apr 2, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D213/80
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for recovering a pyridine-2,3-dicarboxylic acid from a process stream in the preparation process of the pyridine-2,3-dicarboxylic acid in which the process stream is subjected to nanofiltration at a pH higher than 4.5 and the pyridine-2,3-dicarboxylic acid-containing concentrate is utilised. Preferably, the pH is chosen to be between 7 and 9 and the concentration factor in nanofiltration greater than 3. In a suitable embodiment the process stream is formed by the mother liquor obtained in the preparation of pyridine-2,3-dicarboxylic acid by oxidising a suitable quinoline or the corresponding 2,3-lutidine and separating the solid material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.