Process for preparing pyridine-2,3-dicarboxylic acid compounds
US5252739A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Feb 3, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D213/80
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing pyridine-2,3-dicarboxylic acid compounds of the following formula, which comprises preparing .alpha.-halo-oxalacetic acid diesters by reacting oxalacetic acid diester alkali metallic salts with an acid and a halogenating agent or by reacting oxalic acid diesters with halo-acetic acid esters, and then reacting the obtained .alpha.-halo-oxalacetic acid diesters with 2-propenal compounds and ammonia. ##STR1## wherein R.sup.1 and R.sup.2 are, identical or different, a lower alkyl group, and R.sup.3 is a hydrogen atom or a lower alkyl group. The pyridine-2,3-dicarboxylic acid compounds obtained by the process of the invention are useful as an intermediate for manufacturing agricultural chemicals and pharmaceuticals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.