Purification of 1,2-dihydro-6-alkyl-2-oxo-5-(pyridinyl)-nicotinonitriles
US6118002A · kind A · utility
2Cited by
6References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1999 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Mar 2, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D213/84
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention comprises a process for preparing essentially pure 1,2-dihydro-6-alkyl-2-oxo-5-(pyridinyl)-nicotinonitriles from a crude reaction mixture containing the corresponding amide as an impurity. By "essentially pure" is meant a level of purity acceptable for orally administered pharmaceutical products, usually less than 0.1% of any single impurity. At least a stoichiometric amount of an acylating agent is reacted with the crude reaction mixture, and thereafter recovering essentially pure 1,2-dihydro-6-alkyl-2-oxo 5-(pyridinyl)-nicotinonitrile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.