Process for preparing 2-oxindoles and N-hydroxy-2-oxindoles
US6469181B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1995 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Jan 30, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C253/30
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a processes, having practical utility, for preparing 2-oxindoles, N-hydroxy-2-oxindoles, or mixtures thereof comprising: catalytically hydrogenating a 2-nitroarylmalonate diester to produce a 2-(N-hydroxyamino)arylmalonate diester, a 2-aminoarylmalonate diester, or mixtures thereof as a first reaction intermediate; cyclizing, by intramolecular aminolysis of one ester group, the first reaction intermediate to produce a N-hydroxy-2-oxindole-3-carboxylate ester, 2-oxindole-3-carboxylate ester, or mixtures thereof as a second reaction intermediate; and hydrolyzing and decarboxylating the remaining ester group of the second reaction intermediate to produce the N-hydroxy-2-oxindole, the 2-oxindole, or mixtures thereof, wherein the cyclization reaction and the hydrolysis and decarboxylation reaction are conducted in situ with the catalytic hydrogenation reaction without isolation of said reaction intermediates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.