Process for producing pyridine-2,3-dicarboxylic acid derivatives; and novel 1-amino-1,2,3,4-tetrahydropyridine-2,3-dicarboxylic acid derivatives and 1,4-dihydropyridine-2,3-dicarboxylic acid derivatives
US4754033A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 1985 |
| Grant date | Jun 28, 1988 |
| Priority date | — |
| Expiry date | Aug 2, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D471/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing pyridine-2,3-dicarboxylic acid derivatives of the formula ##STR1## is described. The process is based on the cleavage of HNR.sub.10 R.sub.11 from 1-amino-1,2,3,4-tetrahydropyridine-2,3-dicarboxylic acid derivatives of the formula II ##STR2## to give 1,4-dihydropyridine-2,3-dicarboxylic acid derivatives of the formula III ##STR3## and subsequent oxidation of these compounds to obtain pyridine-2,3-dicarboxylic acid derivatives of the formula I. According to one variant of the process, the 1,4-dihydropyridine-2,3-dicarboxylic acid derivatives of the formula III are obtained directly, without isolation of the intermediately formed 1-amino-1,2,3,4-tetrahydropyridine-2,3-dicarboxylic acid derivatives of the formula II, by reaction of .alpha.,.beta.-unsaturated hydrazones of the formula IV ##STR4## with ethene-1,2-dicarboxylic acid derivatives of the formula V ##STR5## and subsequently oxidized to pyridine-2,3-dicarboxylic acid derivatives of the formula I. In the above formulae, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.10 and R.sub.11 have the meanings defined in claim 1. The pyridine-2,3-dicarboxylic acid derivatives of the formula I are intermediates f…
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