Process for the preparation of optically active 4-oxo-1-benzopyran-2-carboxylic acid derivatives and intermediates thereof
US5171865A · kind A · utility
7Cited by
2References
2Claims
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Key dates
| Filing date | Mar 5, 1991 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Mar 5, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C59/68
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of optically active 4-oxo-1-benzopyran-2-carboxylic acid derivatives of the formula ##STR1## wherein X and Y are hydrogen atom, halogen atom or alkyl group, and R.sub.1 is hydrogen atom or alkyl group, intermediates thereof, as well as a process for the preparation of the intermediates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.